Precharge resistor burning up

[kjackmail]

I am struggling with my grandmothers 2013 Club Car Precedent. She called saying her cart started smelling like it was burning when she got home and plugged it up. I checked it out and noticed the precharge resistor was burnt. I replaced the solenoid and the resistor only to have it do the same thing once the batteries were hooked back up. I trailered it home and stopped at a friends shop so he could test the controller with his handheld curtis tester. He said the controller was toast. I found a new one on ebay and installed it today along with a new resistor. Good news! Drove it several miles without issue. Got home and plugged it up. Charger ran for several hours without issue. I then decided to check the speedometer to see how many miles she put on it since I replaced her batteries. I didn't unplug it from the charger to check it. The volt converter is switched so I turned the key and instantly smelled the resistor burning again. My thoughts now are that it might have something to do with the obc since it has the lock out feature while its charging. Grandma also confirmed she plugged it in to charge and forgot to turn the key off. I duplicated what she did after spending $500 to fix it. Any ideas? Did I burn up a new curtis controller or did I replace a good controller for no reason? What else could it be? The batteries were disconnected for about a week while I waited on the new controller to arrive. I think the obc discharged and reset allowing me to re assemble everything without burning up the resistor again. Once I turned the key while charging it created the same fault.

[NoleFan4Ever]

Bumping this back up to get some more views on this and maybe a possible solution(s).

[TahoeDawgZ71]

A short in the motor can cause the pre-charge resistor to get hot as well. Do an experiment. Put the car in tow, disconnect the main positive and negative batteries. Remove the white wire from the A2 terminal on the motor and let it hang, careful not to let it touch anything. Re-connect power and put the car back in the RUN position. If the resistor still gets hot, it's a controller problem. If it doesn't get hot with the motor disconencted, you've got a short in your motor.

[kjackmail]

Thanks for the help! I plan on tearing it down again today and re checking everything. I swapped the obc and got the same results. I haven't tried driving it yet. As soon as the batteries are connected and the resistor starts smoking I unhook it. Tahoe, I will try your suggestion next. I have read thru several of your posts about this. How quick will a shorted motor or wire fry the controller? This cart is one i restored several months ago and its been running fine. I replaced the excel controller with a new one and got the same issue after about 2 miles. I need to find out what is wrong before droping another controller in it. I will follow up this afternoon. Thanks again!!

[kjackmail]

Tahoe, with the white wire unhooked from the motor and everything hooked up I don't smoke the resistor. Finally!! Progress. I have the original controller on it also. I have a stock motor from another build I can put on it. How would I check the Plum quick for a short? It is still under waranty so it can go back for repair.

[NoleFan4Ever]

If I recall correctly, Sergio had guided me (and some others) to test across the field windings and it should be 1 to 2 oms. If you get 0 oms, there is a short in the motor.

[kjackmail]

I have 2 ohms across F1 and F2. Same as stock motor. Im gonna drop the stock motor in it and test again. The lug on the plum quick motor had a little play in it when i unhooked the wires. The nut was tight.

[kjackmail]

Stock motor is in and the resistor started smoking again. Unhooked white wire from A2. Reconnected batteries and no burning. I touched it and its cool. While A2 is disconnected i decided to throw it on the charger to freshen up the brand new trojans and regroup. Oh and thank you plum quick for welding handles on all your motors. The stock one wasn't easy. Charging for about 30 min now without issue. Where do I go from here?

[kjackmail]

Am I wrong to trust that the new solenoid is working? It was a numbers matching replacement from a local dealer. Should i pull it and test with 48v on the small terminals to see if it closes?

[NoleFan4Ever]

I'm kind of at a loss now as it looked like a motor problem but you swapped with a known "good" motor and it still did it.......... Probably need to wait and see if Tahoedawg71 or someone else has another idea to try now.