Trouble With 1976 EZGO

[PM5K]

I have a 1976 EZ-GO golf cart, it's a three wheel model. This is a work unit used at a self storage facility.

Problem started out that the throttle would get stuck, the key switch would not turn the unit off when this happens. One time it happened and the engine started to smoke because it was up against something so it was unable to move, and the switch would not turn it off.

We removed a battery terminal connector which finally turned it off.

After that I made the mistake I believe of leaving the terminal loose, so that it would be easily removed if the problem happened again. I lubricated the throttle linkage so the problem didn't happen again, but the loose terminal, or something else caused it to get so hot that it melted the lead connection. I tapped a new thread on it and fastened it properly, I also put electrical tape over a small part of the battery wire that had melted a bit.

Seemed to be fine for a while, but that particular terminal always got a bit hot, but lately it seems to have gotten worse. One day I was going up a hill and it needed more juice, I pushed it down and a puff of smoke came from the battery. After that it hasn't wanted to work, it makes strange noises if I try.

Any suggestions or thoughts on the issue? I'm posting two pics of the battery setup and the repair I did. The battery on the bottom is the one in question.

[JohnnieB]

For starters, the original problem wasn't fixed. That being the solenoid did not deactivate when the key was turned off.

Ether the solenoid contacts stuck closed or the cart is horribly miswired.

When wired as designed, three conditions have to be exist to close activate the solenoid (close the contacts).
Those being:
Keyswitch ON
F/R lever in either F or R
Throttle pedal pushed.

Normally, lifting foot off throttle, or turning Key off/ or placing F/R lever in Neutral will deactivate solenoid and disconnect battery pack from motor.
Even if lifting foot off throttle didn't stop the motor, the other two should have, so I suspect the solenoid stuck closed and should have been replaced.

Since there has been two incidents with the heat damaged battery terminal, I would, at a minimum, replace both the battery and the damaged cable as well as the solenoid.

And I would verify the solenoid activation circuit is wired correctly. Here is a schematic with the activation circuit highlighted.

[yurtle]

Though the best advice is to find and fix the real problem, if you want to do your "loose terminal trick" the right way, they do make load rated disconnect switches. Several varieties, but the simplest is simply a knife switch.

If you go this route, try and use a cable that is the farthest away from the batteries, but still in the series loop. That will keep sparks from possibly creating water.