My 2008 won’t move (or it moves a few feet and stops). When I press the accelerator I get a sound from the contactor but no forward or reverse movement.
Batteries are new and test OK on the load tester. The charger is a few months old.
The motor is newly rewound.
I’ve read the service manual but do not entirely understand it.
Any help with how to troubleshoot the issue will be appreciated.
Larry
BTW. The dealer where I bought it is no longer servicing the GEM.
Any error codes on the display or beeping from the PSDM?
Does the motor want to move? Or do you have no power to the motor?
What Jrj said ^^^^
In addition -
Has the car been sitting for a while?
(as in- You just came back to your summer house and it has been sitting for a few months)
What tools do you have within your reach?
(I’m thinking a floor jack and/or a couple of jackstands to run the car in place)
(everybody should have a meter at the ready)
No. It hasn’t been sitting.
I have a Jack,and Jack stands as well as a meter.
I have many questions…
(your answers will direct my instructions)
When was it last working well?
The motor is newly rewound
Seriously? They actually rewound the motor? (I have my doubts)
When was this? (“newly” does not help much)
Who did this rewind??
Error codes?
or normal display?
Act any different in DL or Rev?
BTW. The dealer where I bought it is no longer servicing the GEM.
How long ago did you buy this car. Did you pizz him off somehow?
interested in hearing if it has worked since the motor was installed after being “rewound”. Who knows, maybe the brushes were never released and are still in their stowed position.
Yes, it ran great. The motor was rewound with new copper wire, etc. Polaris wanted $2200 for a replacement, GE had a 12 week backlog. (And despite common belief they do still make a version of that motor for industrial use…)
The current problem began as an intermittent one, and now is almost continuous. Yesterday I drove to the end of my driveway and back, then while manuvering into the garage it stopped working.
Thanks
Larry
It last worked well 2 weeks ago. The problem began intermittently and has progressed to where about half the time it won’t move.
The motor was rewound, new brushes, etc. 2 months ago. Ran great for the approx. 6 weeks after the motor work. Rewound by Kiker Electric Motors, the local GE authorized repair facility.
Normal display, ie, no error codes.
I bought the GEM 6 years ago from Terry Thompson Chevrolet, I had no issues with him. He had been a dealer prior to the Polaris purchase of GEM. He simply stopped selling GEM.
I believe I’ve covered your questions, thanks for your help.
Larry
Ok- thanks,
One more Q-
When the car quits, Do you hear the main relay kick back out?
(You know the ‘clunk’ when you press the pedal. That is the Main Relay/Contactor closing when the car is ready to move. There is a slightly different sound to it when it opens back up)
This is a precarious state of dead car testing. One never knows when it will take off and run you or your assistant over for an under car inspection. Keep your ear tuned for that Main Relay 'clunk" as a clue.
If you can, put your car up on stands so it can run in place (but then Murphy’s law says the car will be fine and your car will happily spin the tires).
I’m leaning in the direction that this is a Accel Pedal problem.
Next time it stops, Clamp your meter leads on the Controller connections F1 and F2 and see if any V is being sent to the motor when pedal is pressed. Lay your meter face to the windshield so you can see it from the driver seat. (Maybe tape it in place?)
If no MC clunk, no Volts to the motor, and no wheel spin when pedal pressed, then let’s have a look at the pedal.
Alternate ending
If MC goes Clunk, and you see V going to the motor as you press the pedal (you may even hear some humming from the front of the car) then we will look at the brushes of the motor
(backstory)
We had one very recent issue come through here where the motor tech forgot to release the brush springs from their service position when he put the motor back in the car. It was amazing that the motor still worked for a while but it eventually failed with the same symptoms ar you are having.
I do not hear the relay Kick out, only in.
My controller has 4 large cables labeled pos, neg, A1 and A2. Two smaller wires labeled CF1 and CF2, plus a large 24 or 36 pin plug. I did not get V on the CF1 and CF2 connectors regardless of the pedal position.
What do you conclude? What is my next step?
Thanks,
Larry
Just for a little basic background on the controller and motor:
The controller takes battery input POWER(think big fat cables) and via some small voltage(think 5V) the controller reads throttle pedal position and sends some of that battery power to the motor.
Now an electric motor is pretty much a spinning magnet pushing against another magnetic field. Sometimes the non-spinning magnetic fields are made with permanent magnet(think toy car motors you might have taken apart for the magnets). They can also be made of electro-magnets where an electric current creates the non-spinning magnetic field. In our GEM DC motors, the F1 and F2 connections are the ends of one very long wire which is wrapped in a few loops which create the non-spinning magnetic field. They are called the Field Windings. The A1 and A2 connections are where the majority of the battery power is sent to make the central spinning magnet move and therefore move the vehicle.
The controller will also handle low voltage things like brake switches, sending power to the big contactor switch which connect the battery power to the controller only when it’s needed and a few other things but that’s the basics of our GEM electric car controller, motor and throttle pedal. Basic.
We now return you to your regularly scheduled program.
You should have had something on the F1 and F2 wires.
Doug is right, a better test would be the A1 and A2 cables.
But, going back up to my previous post, I’m leaning towards a foot pedal issue
We should check for power on those wires. I’m not at my desk at the moment, but I’ll sent you the pin numbers and what to expect when I get back. .
Thanks, it helps to know what I’m testing.
Larry
Since I was getting such flaky results at both F!/F2 and A1/A2 I returned my meter to Harbor Freight and bought a better one. Still nothing on either set of wires.
How do I test the throttle assembly? Or what do you suggest next?
Larry
I have a few meters with wire leads which sometimes become loose and give me flaky readings.
I just grab a known power source like a good car battery(if I’m working on the car) or any standard AA, AAA, etc primary cell battery and look for the proper voltage. If I don’t see it then I start looking at the wire lead connections and then turn the volt meter switch a few times to make sure the contacts on the dial are clean.
While I now have a 2008 my experience is with a 2002 but I think the operation is similar even thought the mechanics of the physical throttle pedal is different. In the throttle pedal there’s a switch which opens(or closes?) when you first move the pedal so there will be 2 wires to measure at the 23pin connector. @AssyRequired probably knows these pins. That switch is to let the controller know there’s throttle movement. Next, there is a variable resistor in the throttle switch with a voltage on one side of the resistor, ground on the other side of the resistor and the part which slides across the resistor and changes value as it slides(the wiper) is the 3rd connection.
I would think checking for the switch on/off action at the 23pin connector would be a good idea and then using the proper ground pin in the 23pin connector measure the voltage on the wiper pin while you move the throttle pedal.
No power on A1/A2 or on F1/F2.
I’m looing forward to the pin numbers, and if you will give me instructions on testing the pins, i.e., do I probe the male or female pins or receptacle.
Meanwhile I’ve been searching for a replacement throttle, none of the regular parts sites offer them. I found an old thread where Inwo had them but the last post was that he no longer had them.
I wouldn’t go after the pedal switch not closing.
If that was an issue it would be triggering a -05
You can easily test it by pressing the pedal down and turning key on. This will trigger a -11.
I think this is in the position sensor.
Using the included diagram, locate Pin K (WH/vt wire) and use it for your Ref lead on your meter. Then see if you have ~5v on Pin D (DG/vt wire). Then check your wiper wire and you should see V change from 0 to 5v as you press the pedal.
To do this with everything hooked up you might need to jab a pin into the wire.
If it is easier to access the wires at the controller you will need pins 7, 8, & 9.
I found the white with violet wire (K I assume) and a dark green wire, both at the 23 pin connector on the controller. Are these the correct spots to measure? If so how do I identify the wiper wire?
Is there a numbering system at the connector? I don’t see any markings other than AMP and 23. on one side and 1 and 8 on the opposite side.
Sorry to be so ignorant.
