What's frying my potentiometer micro switch?

[MyCousinVinnie]

So I started this thread but it kind of ran out, and I haven't solved my issue. I have a 1993 Club Car DS with following upgrades:
48V
FSIP 700 amp controller
400 amp solenoid
potentiometer
Heavy duty F&R switch
4" lift
23" tires
Battery pack is fully charged.

A week or so ago, I go to unplug the DPI charger, and use it, and solenoid will not click. I discover that the positive side of the solenoid is missing. I trace it to the potentiometer, which is not putting power out of the micro switch to the positive side of the solenoid.

I then remove the potentiometer. It has a fried micro switch and something that looks like this on the pot itself:

http://www.buggiesgonewild.com/attac...m-img_3619.jpg

I test the pot output and it gives from 0-5,280 Ohms. I then replace the microswitch. and reconnect the pot. I turn the key on and press accelerator. Wire from F&R switch to pot "jumps" as in moves like it becomes energized, but no clicking from solenoid. Then, I notice the micro switch on the pot is fried again. A small puff of smoke comes from the area of the solenoid. Don't know what side.

I don't know if just turning the key on fried the potentiometer micro switch or if pressing the accelerator did. Seems to me it was just turning it on, but who knows. I have tested the continuity of the F&R microswitch when cart is off, and it checks out. I have not checked the key switch, but it seems OK because it is giving my mounted digital voltmeter the right voltage. I have also checked the two small contacts on the solenoid with everything removed from solenoid. It was fine.

It seems that something has a short somewhere. I am hoping it isn't the controller.


I'm afraid to do anything else at this point because I don't want to burn anything up. I have checked the wiring, and it is wired correctly. It's wired the same way it's been wired for a few years after the conversion, so I am guessing it's not that.

Sorry for the long post, but if you have any thoughts, please let me know.

[scottyb]

To fry the pot ms you have to have + and - meeting at the switch.
The puff of smoke at the solenoid is where the trouble is likely coming from.
So you have positive coming from the keyswitch to the pot ms and somehow there is a short sending - from the solenoid.
The only source for - from the solenoid is the small wire from small post to controller B- according to the install diagram I sent for this conversion kit yr ago. Since the cart did run for quite some time I guess either the diode has shorted out or something else has changed ?
Remove the diode and test it for continuity on the bench. It should have continuity one way and not the other. If it has continuity both ways it is the problem.

[MyCousinVinnie]

Scotty, the diagram you sent me when I did this conversion does not have anything coming from the key switch to the potentiometer. Instead, it goes from the key switch to the F&R microswitch. There is one that goes from the key switch to the solenoid. I'll test the diode again, but I don't understand what you mean when you say shouldn't have continuity both ways. If you put the voltmeter leads on both ends, it is going to show continuity or not. I tested it once already and it checked out, but I will try again.

[scottyb]

Battery main + goes to keyswitch and then to the F&R micro switch and then to the pot micro switch(ms) and then to the solenoid.
That is 3 switches total that have to work to activate the solenoid (+) side.
The (-) side is a constant supply to controller B-

The diode is a one way path for current.
Test it for continuity - then swap ends and test again.
You should get continuity one way and not the other way.
If you get continuity both ways - replace it with a similar 3 amp 1000v diode

[MyCousinVinnie]

I'll checked it. Based on what I can tell, the diode has continuity on both sides. That is, if put the red lead on the positive side of the VM and the black on the black, I get continuity. If I switch them, same thing.

I also bench-tested the solenoid. I get a click, and I get continuity at the large terminals. I guess that is good. I'll switch the diode out, install a new switch and see what happens.

Also, is there any way that something caused the diode to go bad, like the controller, or something else? Can a bad diode damage the controller? Thanks.

[TahoeDawgZ71]

Your diode is bad. It should only have continuity in one direction, not both.

[scottyb]

Originally Posted by TahoeDawgZ71

Your diode is bad. It should only have continuity in one direction, not both.

Exactly so replace the pot ms and put the diode in the trash... if the cart runs get a new 3 amp 1000v diode and boogy on down the road Mr.