Resistor very hot with key off?

tws31

Hi,
I recently purchased a used '99 Club Car DS 48v cart. I bought it with dead batteries, the owner claimed it was working ok before the batteries died. It looks to have been sitting for awhile just judging from appearance. I purchased a new set of batteries, cleaned up all the battery cable ends with sandpaper, also disconnected all the cables going to the controller and the solenoid and cleaned them too (did them one at a time so I would get them put back where they were). Also used new bolts to fasten the cables to the controller as the old ones were really rusty. My problem is, a couple minutes after I connected the batteries I started smelling something getting hot (sort of like how a heater smells when it hasn't been used in a while). I figured out that it was the resistor on the solenoid. I disconnected the red battery cable as quickly as possible (was connected less than 5 minutes). What would likely be causing this? The key switch was off, and the cart was in neutral the whole time. I would appreciate any help and suggestions. Thanks.

BGW

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whizzo

That is the prechrage resistor that powers up the controller before the rest of the power circuit.

If this resistor is hot...like "smokin".....I expect that it is faulty.

Best to have it out and measure the value....and compare with what it should be.

cheers

scottyb

Another possibility is the cart is trying to run (in the 'off' position) and drawing power thru the resistor. To test this theory shift the cart to neutral and see if it stops heating up the resistor.

tws31

Ok so I removed the resistor from the solenoid and checked it with a meter. It showed .238 ohms if I had it on the right setting. Does that sound right?

tws31

The cart was in neutral as well as having the key off.

scottyb

Continue testing with the resistor off for now. Does the solenoid click when you try to go? If not start with troubleshooting the solenoid activation circuit. You might have a bad micro switch (MS) on the F&R or in the V-glide.

ltmoeller

I went thru this on a 99 cc with the exact same issue.turned out the controller had a short in it.
Just sayin.
Tom

whizzo

The resisto should be in the reigon of 300ish ohms. 270ohms is common for 36V carts.

even if the controller is short circuited the resistor should not "overheat".
It might get hot...but it should be fine.

there should be a link to a manual for you cant somewhere here..it should give you a correct value for your resistor.

The purpose of this resistor is to provide only sufficient current to charge the capacitors in the controler relativly slowly.

cheers

tws31

First, let me say thanks for all the help everyone has been providing! It's much appreciated!

Yesterday I put the solenoid back in without the resistor. I tried turning the cart on and trying to get it to move, but it wouldn't do anything. The reverse buzzer worked, but that's it. I listened for the solenoid to click and it wasn't, so I checked for both voltage and ground on the little red and yellow wires. Both are present when the pedal is depressed so I guess I need a new solenoid. I also noticed that what I think is a voltage reducer for the headlights was directly connected at the controller's B+ terminal and not run through a switch as I've read it's supposed to be. I disconnected it just in case it might have been having problems and maybe was the cause of the resistor overheating.

Were you having any other symptoms? Would the cart still move even with the controller being shorted? I sure hope I don't have to buy a new controller cause I've read they're pretty expensive...


I've read in several places where it's supposed to be a 250 ohm resistor, but don't know for sure that that's correct. Take in mind when I first connected up the batteries that I didn't leave it connected very long (under 5 minutes) so I don't know how hot it would've eventually got. It wasn't smoking when I unhooked the batt cable, just was very hot to the touch and had a hot smell.


Sorry for the long post...

tws31

Update:

It turned out that the solenoid wasn't bad after all. Just to make sure I ran a jumper wire to each of the coil posts on the solenoid (one at a time). The positive (small red wire) made no difference, but when I grounded the post where the small yellow wire connects the relay would click perfectly when the pedal was depressed.

As far as I can tell this was caused by the OBC not getting power. The charger wouldn't start when it was connected, and I was trying to troubleshoot that, and I found the pin for the red wire in the three wire connector that runs inside the OBC was partly pulled out and not making contact. Fixed that and now the charger starts and the cart moves too!

I now have a new problem that I'll start a new thread about in a few minutes.

Thanks for all the help on this guys!