Category: Ask the Guru

ATG (SepOct15) - MCORs

QUESTION: M.D. Writes: Can you please supply some information about Club Car MCOR’s.

ACCORDING TO ROGER: Well get ready to be entertained! I am not quite sure anyone knows exactly everything about the MCOR maze. It is sort of like “what computer do I use on a Club Car”? I bet even Club Car gets confused! Testing MCOR’s is the same across the board. They all have the same three wire high side, low side and wiper, as that has not changed. However, values are not the same across the board. Resistance values can be 7K to 1K, 6K to 1K, 5K to 0 and so on. So if resistance values are different so will voltage values. Throttle mapping, tuning, deadband can become a nightmare. So you really have to pay attention to exactly what system is in the car. Meaning IQ, Excel or i2. The controller being used has to match the input values. Then throw in that odd ball year from 2008.5 to 2009.5 that had a TPS throttle (Throttle Position Sensor). Understand, just because the car has a Shunt Wound Motor System, they are not all the same! Then it gets even better. Some model cars based on year, and system can have a parasitic draw/input on the negative inputs to the MCOR and Speed Sensor. Meaning another device is using the same negative. What happens is a feed back into the controller logics. When that happens the controller shuts down. Sometimes we have to move the MCOR negative and Speed Sensor negative to a hard negative. That just means we are not supplying negative from the controller. It appears there are three versions of the O.E.M. controllers that use an MCOR. IQ is a Black box. Excel is a Gray box. i2 is a White box. So you can kind of use the box color as a guide for replacement without modifying the wiring for figuring out what MCOR to use. Typically, a White controller will be a more conventional 5K to 0 wipe. The rest of them, Black and Gray are all over the board. We are already at generation 4 on MCOR’s and again that one seems to be the newest direction.

When I say 5K to 0 I mean when the MCOR micro switch “clicks” you should see 5K. So there is a relationship between when the micro switch “clicks” and the Potentiometer begins it sweep. There you have it a nightmare for controller manufacturers.

I know when speaking to customers I ask a lot of questions in order to get identity. Once I know the identity of the system, trouble shooting or parts replacement can be done much easier. So, basically, you will do the same thing. Do not just order a part based on it being a 2004 or 2013 year. Check what system the car has and then order. We are talking about MCOR or controller parts not front ends and rear axles. Those type of parts are based on make, model, MFG code or serial number.

MCOR’s do not all have the same connector. Some have a 3 pin triangular Deutsch Connector and one 2 pin Deutsch Connector. Some have a flat 6 pin connector (TPS models) and some have in-line 3 pin and 2 pin connectors. To help with choices we are looking at building adapters for the different configurations. We are looking at building MCOR’s that have one standard value.

Stay with me on this because we are not done yet!

How about the pedal group the MCOR mounts to. Is it a generation one or generation two? So guess what the MCOR’s will not interchange! Once again, you have to look and see what is on the car. Maybe, that pedal group was changed and that will mess up your order for sure. My advice, once again, is look first and do not order something based on make, model, MFG or serial number (this is only a guide). The MCOR/Controller/Motor is a tad bit tricky as you can see. Should you need assistance, I do have hundreds of documents on that subject. Just email me and I can send you trouble shooting or identity information.

Tech Tip: (write this down) LOOK FIRST!

ATG (JulAug15) - Bench Testing Solenoids

QUESTION: Can you tell me how to bench test solenoids?

GURU: You know, I guess that is something I should cover. It seems no matter how I write it; some people just do not get it. So maybe this is a better way to approach this. I think where people get confused is understanding how the solenoid is activated. So let’s simplify that a tad.

A solenoid, contactor, relay or whatever you want to call it is nothing more than an electrical on/off switch. When you flip your light switch on at your home that is a switch. A mechanical switch activated by physical force. When you turn a key switch on your automobile to the start position you are sending a voltage signal to the car’s solenoid. You are electrically activating a solenoid to start your car. Solenoids have all sorts of configurations, all sorts of voltages and sizes. But they all do the same thing they make and break an electrical circuit for a on or off mode.

In order to understand some basic things about bench testing let’s point out some of the major parts. Large terminal or lugs are used for heavy cable connections. Small terminals are used for solenoid activation. Footprint just means the size and shape of the mounting area or size. Inside the solenoid is a movable iron core. Inside is a wrapping of copper wires called a field. Hundreds of strands of wire make up a field. Usually, a solenoid based on application, will be a single pole - single throw or a single pole - double throw. This just means the number of contacts used between the large terminals or lugs. Most common are a normally open set. Some have a set of normally open and a set of normally closed contacts.

How the contacts make and break are based on the voltage being applied to the small terminals. That voltage passes through the fields creating a magnetic field. This magnetic field pulls the iron core downwards or upwards depending on manufacturer. This movement pulls the contacts together and causes voltage and current to flow. Once voltage is removed the field collapses and the contacts open. Very simple and efficient way of an electric on/off switch.

Bench testing begins with knowing what the coil voltage is. Most common voltages are 6, 12, 24, 36 and 48 volts. Some voltages are dictated by what the voltage of the car is. Let’s say we have a solenoid rated at 36 volts. We could just connect the solenoid to 36 volts and see if it “clicks”. While in a “clicked” position you should read continuity across the large terminals or lugs. If not the contacts are worn out. What if the solenoid did not “click”? Usually, that means the solenoid coil is open. Either way you have a loss of contact or coil activation, the solenoid is defective.

You can also test the solenoid coil with a VOM (Volt, Ohmmeter). On a low scale ohms say 200 connect across the two small terminals. You should see some sort of value in terms of resistance. 55-60 Ohms or 180-190 ohms. The resistance value is based on manufacturer, iron core size, and voltage rating of the car system. I cannot tell you an exact resistance value because of that reason. I can only say you will read a very low resistance value. It takes very low current to activate a solenoid. Usually, on the side of a solenoid it shows the manufacturers name and model of the solenoid. You can go on-line and find the exact values. But the bottom line is; if you do not read a resistance across the two small terminals the coil is open.

Large and small terminals usually are not polarity sensitive unless a diode is used between the two small terminals. For resistance values remove the diode. Sometimes you will see a resistor across the large terminals. Remove the resistor for testing.

If no problems are seen with the bench testing the problem is in the car.

ATG (MayJun15) - Golf Cart vs ATV

QUESTION: Why Should I buy a golf car and not an ATV for off-roading?

ANSWER: I advise people to determine how aggressive do they want to be.

What do you expect, and what is your budget. If you intend to be hard core and load it up and get crazy consider a gas car or ATV. If you intend to be conservative and build your own, consider a golf car. I can only advise you of what I have experienced. I am 63 years old and still love that outdoor off-road experience. However, I am totally convinced of the golf car aspect of it as I have lived it. I have enclosed several pictures of myself and others enjoying the outdoors. The pictures you see are actual off-road with electric golf cars with an ATV leading the way.

Notice I did choose the ATV so I could see inexperienced people try the golf car adventure. For the most part for a lot less money and the fun of building it the golf cars went everywhere the ATV went.

However, I did draw the line when I buried the ATV in a pit LOL. As I drained water from the engine the others kept on rolling. And not to knock an ATV in anyway, notice a golf car is pulling that ATV out of that pit. Again, if you expect a golf car to be an ATV it is not. But the fun is still there! We ran those electric golf cars in mud, water, mountainous terrain for three hours continuous duty. The only casualty was me drowning my ride. Electric golf cars are great for hunters and recreational activity. I have proven over and over that electric cars do work in the wild and off-road. It only gets better as we evolve into AC motors and controllers of 600 amps with higher voltages. Just determine how aggressive you wish to be.

guru

ATG (MarApr15) - How to Test a 2010 48V TXT

MD writes: How do I do testing on a 48-volt TXT 2010

According to Roger: TXT 48 Volt Electric Car 2010 and Up:

Make sure you turn the run/tow switch to tow if disconnecting the battery pack for any reason or you can see catastrophic controller failure! Make sure the rear wheels are off the ground for safety. Wear eye protection! Do not jump things out!

To start you must confirm the following:

You must see above 48 volts on the battery pack as 48 volts is a dead pack. 52 volts is fully charged. Yes the car will run at 48 volts, but not long.

You must have a voltmeter with self-penetrating leads to test pin-out voltages.

Self-Penetrating lead clips. You will need the lead wires as well. Electronic stores carry these. TP82 Clips and TL222 Leads.

Leads

Confirm you have 48 volts positive at pin number 9 red wire on the 16 pin connector (run/tow in run position). If not fix that wiring circuit.

Confirm you have 48 volts positive at pin number 10 yellow wire (with key switch on). If not fix that wiring circuit.

Confirm you have 48 volts positive at pin number 6 green wire (key on in forward and foot pedal pushed). If not fix that wiring circuit. If voltage is present before you push the pedal the switch is stuck in the on position and will cause SRO/HPD and shut the logics off. All three voltages we just tested must be in sequence.

Confirm you have 48 volts positive at pin 8 green wire (key on in forward). If that voltage is missing then we need to confirm 48 volts positive is on the center terminal (gray wire) of the forward and reverse switch. If that voltage is missing repair that wiring circuit. The same thing applies to pin 16 orange wire.

Confirm you have 48 volts positive (may be a tad under that) at pin 5 which is an orange/red wire and can be an off red color. If that voltage is missing the disable circuit is defective in the charging receptacle. To test remove the blue wire from the off red wire. Supply a 48 volts positive to the off red wire. If the car runs you have found the problem. If the car still does not run we test other circuits as follows.

With the key on place a voltmeter on the small yellow wire on the (small terminal) contactor. You must read 48 volts positive, if you do not fix that wire circuit. If you do read 48 volts positive move your test lead to the other side (blue wire) you should read 48 volts positive. If you do not the coil inside the contactor is open, replace contactor. If you read 48 volts positive then push the accelerator pedal (key on in forward). You should see that blue wire turn to a negative potential. If it does not and all other pin-out are correct we either have a motor, speed sensor, ITS or controller issue. This section was for a contactor that does not “click”. If it does “click” we have issues with the ITS, or motor.

ITS at pin 1 white wire should be a 14 volts +/- positive output to the ITS module. If that voltage is missing the controller is defective. If that voltage is present check for positive .3 volts +/- at pin 2 black wire. As you push the accelerator that voltage should increase close to 2.94 volts +/-. If it does not the ITS is defective. If that voltage is correct test the motor as per motor testing. Disconnect the F1 and F2 field connections. Place an ohmmeter across the field terminals. You should read 1 to 3 ohms, and if you do not you have motor problems. Check all four motor terminals with and ohmmeter to ground (low ohms). If you have a terminal that is grounded to the frame, repair the motor. It is all about following procedure and the car diagram to find the known potentials and confirming them. Make sure you have the tools to do the job!

ATG (JanFeb15) - Test Stand (Part 3)

This one is much more simple than Shunt Wound Systems and takes a little less time to wire and make cable connections. Parts you need are a manual shifter, contactor (single pole single throw), Potentiometer, ITS, motor/drive unit. I chose to do that just a tad different so battery disconnect is not needed when switching from 36 volts to 48 volts. So that is what I will show you below. Also, I just wanted you to know you can use a manual shifter if you wish.

I am using three single pole double throw contactors and two single pole single throw contactors. For activation I am using two single pole single throw switches and one single pole double throw switch.

Here is the sequence of activation. I have installed a 36 volt lead into the contactor and a 48 volt positive lead. Then on the negative side I connected direct to a single pole single throw contactor. By doing a connect to negative that way, it allows me to open the circuit so disconnections can be done without the dreaded sparks. I added a voltage selector switch and an activation switch. By activating the voltage splitter contactor the appropriate voltage can be selected. I also added a light that indicates the system is activated and also discharges the controller at shutdown. Just use a 48 volt bulb in a taillight. Notice the activation circuit remains at 48 volts so only 48 volt contactors are used. Wire colors are your choice I just chose what was available at the moment. It is recommended to use a flexible 6 gauge cable set. All activation wiring can be 18 gauge. A single pole single throw contactor can be added for shorting the armature so full stall current can be seen. Or use a mechanical brake system to apply a load. Everything is dependent on how elaborate you want to be. Sometimes simplicity is the best way. A word about safety, be sure to wear eye protection and pay attention to voltage potentials as high voltage and current can burn skin really bad!

Note: input voltage to KSI circuit is wired to the Voltage Splitter for correct KSI input. As you wire the system make sure you do that. It matters in terms of controller activation some controllers will not activate if the wrong voltage is seen at the KSI input.

activation-wiring-tstest-stand-series-new-version

ATG (Nov/Dec14) - DS Not Moving

This is a multi-part question and answer.

Question: I have a 1999 Club Car DS that when I turn on the switch and put it in F or R and depress the foot pedal I can hear the solenoid click but it will not move at all. When I replaced the controller the solenoid was not clicking. Now all I get is the click but nothing is moving. I checked out the motor and it tested well but I did have another one here so I replaced it just to be sure. Still is not running. I looked at the F/R switch and it seems to be working properly. Any ideas?

Roger Asks: Series or Shunt? Meaning, does the car shift with a lever or rocker switch? I have to know that before I comment.

Roger, It has the rocker switch, and it has two solenoids. The second solenoid without the spring resistor (the driver side solenoid has the spring type Resistor) is not working at this time. I am going to swap it with a new one and see if that helps. I am not very familiar with this specific setup and I am not certain what that second solenoid (on the passenger side) does. But I do know that through all of the functions it never made contact.

Answer: That is called Regenerative Braking System 2 (Power Drive Plus) and is the second generation Shunt Wound Motor System often referred to REGEN 2. Now we can talk.

System Pin-Outs:

To test this system it is just a matter of confirming pin-out voltages. Notice the controller has a 23 pin connector and each pin has a voltage value. You will need self-penetrating wire leads as shown in the photo. The industry has moved into that style of testing and you can purchase at Grainger, Digi-Key, Mouser Electronics or any electronic supply warehouse. The right tool makes the job easier. I made a view of the 23 pin for ease of recognition and as a guide. But refer to Club Car chart for exacts, and the connector is numbered.

As with any trouble shooting procedure you must confirm the Known Factors. Later you look for Unknown Factors.

Known Factors:

Knowing what positive inputs we see at pins 1 and 2 if we do not have a positive voltage at that point we have an open in the Run/Tow wiring and or switch.

Knowing what positive input we see at pin 3 and if we do not have a positive voltage with the accelerator pedal pushed the accelerator pedal wiring or switch is open.

Positive input should be seen at pins 4 and 5 and if we do not we have loss of voltage in the forward and reverse wiring or switch.

Used on Club Car is a positive OBC input to power up the system (pin 6). It can also be used as a key switch positive input.

The Potentiometer inputs at 7, 8, and 9. Pin 7 is the wiper, pin 8 is negative (low side) pin 9 is positive (high side). The voltage value is listed in the appropriate PDP diagram. Or you can do a resistive reading on a 20K scale at pins 7 to 9. You should see 5K to 0 pedal up to pedal down.

Positive pulse at pin 14 from the speed sensor. This is typically a 5 volt pulse and is very difficult to see and difficult to test. Mainly just confirm a voltage is present.

Positive voltage at pin 15 that Club Car says in 5 volts G.E. refers to it being 12 volts. Just confirm you have a constant voltage. If that voltage is missing that means the controller is not sending that voltage.

Negative output at pin 16 to the speed sensor. If missing the controller is not working based on good inputs.

Negative output at pin 17 for solenoid activation. If missing the controller is not working, inputs missing or computer lock out is seen.

By knowing the pin-out values we can locate the problem.

The unknown factors missing voltages. As an example of missing voltage say at pin 3. That is not the controller that is the foot pedal circuit. Foot switch or associated wiring. What other wiring or switches are in that same circuit? Looking at the diagram we see a key switch and run/tow switch in that same circuit. So you have to test that circuit to confirm where voltage is missing.

Unknown would be pin 6 output/input from and to the on-board computer. That is the lockout from the computer and shuts car down when on charge. What I do on those is cut that yellow wire and then, connect a positive to it and see if the car runs. If so you have a defective computer. See the correct PDP diagram for other computer wires needed for by-pass (not just signally the yellow wire at pin 6).

So finding Unknown Factors are done after Known Factors is completed.

Yes the customer did repair the car!

ATG (Sep/Oct14) - Bench Testing Cont’d

If you have any questions about my articles or our products (or just want to chat about golf car repair), feel free to contact me at guru@golfcarnews.com.

Question: S.K. Writes: Mr. Kramer can you please help with some sort of bench testing for controllers so we can run them before we install them?

Answer: Continued from September/October 2014 issue. This time around we’ll address a shunt wound motor test stand and wiring.

Parts:
1 Single Pole Double Throw Switch
3 Single Pole Single Throw Switches
1 5K to 0 Potentiometer (Linear 3 Pin)
1 Project Box (Plastic)
1 1/4” Knob
1 Sheet Of Wood Or Plastic (36 X 18 X 3/4”)
1 Stand (36 X 25”)
1 36/48 Volt Battery or Ferro-Resonant Transformer
1 Assortment Of Color Tape
1 Assortment Of 18/22 Color Wire
1 Shunt Wound Motor (Closed Case)
1 36/48 Volt Contactor
1 In-Line Fuse Holder
1 Controller Mounting Plate (E-Z-GO Heat Sink)
1 Assortment Of Six Gauge Cable (Lugs)
1 Assortment Of Wire Ends
1 Speed Sensor Lead Cable
1 Assortment Of Molex Connectors And Pins
1 Amp 23 Pin Male Connector
1 Pre-Charge Resistor (For Controllers That Require)
1 Diode For Contactor (Spike Protection)
1 ITS Module

The Project Box, Tape, Switches, Knob and Potentiometer can be purchased at Radio Shack. Wire, Cable, Lugs and Wire Ends you should have in your stock. You can use a motor from your stock just add the end plate. Molex and AMP Connectors, Pins and Sockets can be purchased on-line at Mouser, Digi-Key or Allied electronics. You can build a table or see what Harbor Freight or Lowes has. The battery is Lithium-Ion and may not be in your area and it is handy. Any of your old Ferro-Resonant battery chargers you can use. All you need is the transformer and diodes. Power connections are connected as Manufacturer recommends.

The key to any test stand is knowing the switch pin-outs and controller pin-outs. It is important to know the sequence of operation. Based on any given system whether it is GE, Alltrax, or Curtis each one has its own pin-out configuration. As you build your wiring adapters you must consider that. Basically, you will need as I call it the “Known Factors”. As you can see by this simplistic diagram are a sequence of known factors. Power supply, run/tow, key, forward/reverse, throttle and potentiometer. Typically, you will see 8 to 10 potentials you will need to work with. Every controller has to have a positive input voltage. Usually, that is either direct from run/tow, key switch and foot switch. Then you start with forward/reverse inputs the system uses. If you look at this drawing you only see positive inputs and outputs. Negative pre-exists in controllers internally. Negative controller output usually only consists of just one or two signals. Such as drive the main contactor or back up alarm. For this test stand we only care about contactor input. Know what this input is and label it clearly. It is important to have the correct wiring diagram of the system you are working on. Each car manufacturer has diagrams that clearly show the controller pin-outs. Taking those pin-outs and aligning the adapter pins with controller pins can be easily done. Think ahead and look at each configuration and plot out the different adapter to controller circuits. Unknown factors can be throttle inputs or speed sensor inputs. If you look at the simple POT (potentiometer) in the drawing it is a basic linear design and can be used as 5K start or 0 start depending on full turn clockwise or full turn counterclockwise. Other inputs can be voltage or inductive design. You just have to know what the manufacturer is using.

The reason you want to make removable connections is so you can use the switch box for trouble shooting golf cars. As an example the above box is for E-Z-GO ten pin Controller. Connect the Molex ten pin to the controller. Connect the red wire to battery positive. Connect the Blue wire to contactor negative input side. Connect the Yellow wire to contactor positive input side. Turn switch K (Key) on, then switch T (Throttle) on. Connect pins 1 and 2 to an ITS module. If the car runs from slow speed up to high speed this eliminates the Controller, Motor and Conductors. Result, this is telling you there is an issue in the car wiring or throttle. Note: use a steel rod to simulate throttle.

You can do this same thing with the other Switch Box and adapter per application. The Potentiometer I chose is usable either as 5K to 0 or 0 to 5K wipe. It can be wired as high or low side input with center wiper. If you wish to have the car run in reverse push switch R. If you wish to test the ITS circuit just clamp a wire piercing test lead to the throttle wires pin 1 or 2. You should see 14 volts on one side and .9 volts on the other pin. As you insert the steel rod you should see that low side voltage of .9 (lower than 1 volt) climb from pedal up to pedal down close to 3 volts. If you see this voltage movement then the controller is working in terms of throttle. If you do not see that voltage the controller or ITS is defective. I would use a diode in pin 10 wire and key switch input. And do not forget some brands of controllers require a Pre-charge resistor and a KSI Diode for Contactor coil voltage spikes.

For further assistance just send me an email and I will help you.


ATG (Jul/Aug14) - Bench Testing

If you have any questions about my articles or our products (or just want to chat about golf car repair), feel free to contact me at guru@golfcarnews.com.

Q: S.K. Writes: Mr. Kramer can you please help with some sort of bench testing for controllers so we can run them before we install them?

According to Roger: For some reason this suddenly has been a hot topic. It seems you are not the only one with that request. A test stand not only speeds up processes it helps you with troubleshooting. You will find by taking the time to build one it also becomes a training aid for your techs. It can be used as a Demo Unit for your show room to explain the features and benefits of the motor system you are selling. Ultimately, that is our goal, profit from sales. The more you can educate your clients and personnel, the profit levels will increase. This may become a two or three part answer as this is a very large subject and will not fit into the allotted space I have. That is why sometimes I write condensed versions of things. This one we cannot do that.

So to start with let’s talk about materials. This will depend on how elaborate you want to be.

Switches:
3 Single pole single throw rated at 3 amps will suffice (Mini)
1 Double pole double throw rated at 3 amps will suffice (Mini)
1 Plastic project box 6” X 3” X 2” (you can use smaller just make sure it will accommodate all of the parts)
1 Linear potentiometer rated a 5K to 0 (1/4” shaft)
1 Knob for potentiometer (1/4” ID)
1 Contactor (solenoid) rated at 36 volts
1 Contactor (solenoid) rated at 48 volts
1 Shunt wound motor (closed)
1 Series wound motor (closed)
1 Non conductive mounting board 36” X 18” X 3/4”
1 Push cart or metal frame to mount the parts to (Harbor Frieght)
Spools of 18 gauge wire of assorted colors
Assorted wire ends
Assorted cable ends (6 gauge)
Roll of cable (6 gauge) 15 to 20 foot depending on system (series or shunt)
10/12 Gauge wire (red and black) and cut to length (shunt system)
2 Molex nine pin connector (optional)
2 Single pole double throw contactors (solenoids) for series systems or use a manual forward/reverse shifter. Contactors will give a cleaner look. 36 and 48 volt.
1 Diode rated at 3 amps
1 Pre-charge resistor rated at 250 ohms
1 Ferro-resonant 20 or 30 amp charger (two connected in parallel will double output for amperage)

The mini switch can be found at Radio Shack along with the potentiometer and knob. The contactors should be in your golf car stock. The motor can be ordered through your sales representative. Cables and wire you should have in your warehouse. You can use a PB-6 Pot-Box but that limits you to a 5K to 0 wipe. We will discuss resistive wipe, ITS and voltage for throttle inputs as we go along. In your stock pile of old battery chargers you should have a charger. Or you can use batteries if you have extra and the room to fit them.

ATG (MayJun14) - Oil Changes

Q: G.H. Writes: What is your recommendation of a generalized oil change? I would like some sort of hand out for my customers.

A: dirt! Over time dirt and sludge can build up inside the engine and one way to remove this unwanted substance is to change the oil! Before we begin let’s talk about safety. Please wear safety glasses and use the proper lifting equipment and jack stands to support the car. Dispose of the oil in an EPA approved manner. Most local oil change shops will take your old oil for disposal.

Begin by cleaning all areas that you will be working around such as the dip stick, drain plug and fill port. The three areas mentioned can allow dirt to fall inside the engine as you remove them and we do not want that. With the car raised high enough and supported with proper jack stands locate the oil drain plug and make sure you have a drain pan in place to catch the used oil. Some cars such as the TXT E-Z-GO brand uses a three bolt oil screen for oil removal. If you are not sure refer to your owner’s manual for the type you have and the location. Once the oil is drained clean the area and make sure the seals and or gaskets are in place and reinstall the hardware. We can now install new oil to the engine. Note: Club Car uses a spin on oil filter and should be changed at this time. Be sure to coat the new filter seal with oil before installing. Your owner’s manual will tell you the proper amount of oil for each brand of car. It is important that you DO NOT over fill the engine with oil! Wipe off any oil spills and double check all installation points for tightness and sealing. Test run the engine and look for any leaks and document the date and or hour meter reading so you will know when to change the oil again. A good rule of thumb is to change the oil every 200 to 250 hours of operation; depending on the conditions the car is used. Harsh conditions such as real dusty and off road require you to change the oil more often. The 4490 hour meter is a good device to install on your car for monitoring the hours of use. A 4624 is a mounting bracket for ease of installation.

The use of good 10W-40 oil with a SAE SF, SG, CC rating will work well. Since we are dealing with air cooled engines and if you are using your car in very hot climate straight weight 30 oil can be used. Oil usage is less with straight weight oils than the multi viscosity. Another good option is to use a good synthetic blend such as Valvoline Dura Blend. Brand of oil is your choice and in some cars that are new you must use the recomended viscosisty of the manufacturer to retain warranty.

ATG (MarApr14) - New Motor

Q: Al writes: Mr. Kramer, I have a Marathon model electric car, I recently put a new motor on and it does not go any faster than it did. Can you offer soje suggestions?

A: Before spending anymore money on the car let’s talk about some area’s of concern. There are hundreds of those old cars across the country and being used in Construction, Hunting, Off-Road, Farms and you name it. So it is not a waste of time to repair the car as it can still perform as well as some of the newer models. Before we start I want you to understand a stand alone motor only is only one part of the car. That motor is a series wound motor and will only be as powerful as its weakest link. I have taught for years that electric powered vehicles are powered by a system. You have to think of it as a system and consists of a motor, controller, cables, contactor and the battery pack. With that said let’s look at some things.

Batteries:
Perform a complete load test on the batteries. This is done by applying a continuous 75 amp draw on the batteries for a long period of time. So you must use a devise that can sustain that constant load. Automotive testers are not designed to do that. While monitoring each battery during a discharge for a period of 90 to 100 minutes you can determine the battery pack condition. Typically, a pack that can perform up to 60 minutes is deemed to be good. However, you will have a noticeable loss of run time. Anything under 60 minutes, look for a single defective battery or batteries. If you have a load applied and a single battery cannot produce its rating then you will see that in loss of speed and torque very quickly. So your starting point is to confirm you have a good working set of batteries!

Cables:
Cable size and fitment matters a lot. For a motor that is demanding high current draws the conductors have to be large enough to deliver that current demand. Any kind of resistance to current flow will affect motor performance. Such as a loose connection, undersized cables or corrosion. Usually, you can just drive a car for 10 minutes or so up hills or hard usage. Then feel of all the connection points and if you find a really hot area, I mean it makes you let go then you have found a point of resistance. Determine if that spot is loose, corroded, undersized or just worn out. Repair that area.

Controller:
Solid state controlled cars not resistor controlled cars only. Do not use a speed motor on a resistor controlled car! So at this point let’s not confuse those two cars with this suggestion list. A controller on a Series Wound Motor system will not increase the speed of the car. The motor determines the speed/torque of the car. However the controller must be of a size that can deliver the amount of amperage the motor demands. So if you install a high speed/torque motor you must also install a controller of a size (amperage) that can keep up with motor demand. Stall test the system and see what amperage the controller can produce. The use of a shunt or amp clamp can be used to do this. Low current limit means a controller is defective or a motor has some brush issues or internal issues. Low current limit can be a result of a Potentiometer that is out of adjustment or is worn out. Test the Potentiometer for a 0 to 5K wipe. Once you have a correct wipe recheck the controller current limit. If it is still low check the motor for defects. If the motor is correct than replace the controller. Replace with a controller that is rated high enough for use with the motor being used.

Contactor (Solenoid):
Again the current demand created by the motor travels through the contactor. The contactor contacts must be of a size that can carry that load. If the contacts are too small than resistance is created and loss of power is noticed.

Motor:
Motors used on 36 volt system are a tad bit hard to work with in terms of high torque and speed. Yes, you can do that it just is not as good as you will see with 48 volts systems. So, if you are comparing your car to someone else’s car make sure you are comparing apples to apples. A new motor takes some time for the brushes to fully seat in. The speed of a car can change by 3 or 4 mph when the brushes fully seat. Think of it as you would an automobile engine with new rings. Take it easy for a while and give the brushes time to seat.

So my tips are:
1) Do not base speed and torque on motor only.
2) This is a system and must have the correct system parts, motor, controller, contactor, batteries and cables.
3) The Potentiometer has a large part to do with the cars speed and torque.
4) Mechanical condition of the car can affect the speed and torque of the car. Low tire pressure, wheel alignment, dragging brakes, worn axle bearings. Correct any mechanical condition that may be needing repair,
adjustment or replacement.

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