1992 EZGO 36V Marathon erratic speed problems

[mwalker007]

Thanks, I have changed out the potentionmeter and the switch. I will now try the controller with the DVM. Thanks and I'll report back.

[rabbitreborn]

Originally Posted by mwalker007

Thanks, I have changed out the potentionmeter and the switch. I will now try the controller with the DVM. Thanks and I'll report back.

The readings would be from the wires, not the pins on the controller...... Sorry I wasn't specific before.

[scottyb]

IF the problem occurred immedeately after you changed the pot out... you may have the reverse or opposite signal pot... they come in 2 varieties.
0-5000Ω signal and 5000-0Ω signal

[mwalker007]

Originally Posted by rabbitreborn

you have 2 separate issues. The first is the batteries needing to be replaced. As for the rapid surge in speed , that can be caused by 2 things. Either the potentiometer has gone bad or the controller has gone bad. Pull the #2 and #3 pins from the top of the controller, set the DVM to Ohms and take a reading with pedal up (should be 0 Ohms) slowly depress the accelerator and you should see the Ohms climb slowly to 5k at full pedal down. If the resistance jumps instantly to 5k with the pedal barely depressed, the Pot box is bad. If it operates correctly, the controller is bad.

I hooked up the meter to the "new" potbox I just installed and it read .3 with the pedal up and moved up to .5 with the pedal all the way down. It appears that the potentiometer is not zeroed out or is bad. Can they be adjusted or is it just bad? The controller never registered anything when I checked it.

There was a resister I didn't replace when I replaced the old potentionmeter, could that effect it as well. Thanks for your help!

[mwalker007]

Originally Posted by rabbitreborn

The readings would be from the wires, not the pins on the controller...... Sorry I wasn't specific before.

I understand now what you were saying on how to test the pot box. Thanks

[mwalker007]

I unhooked the pot box from the speed controller and pushed the pedal down and the cart took off! (?) I thought if you disconnected the pot box the speed control would not work. Is this supposed to happen?

[scottyb]

Right you are - something wired wrong... post some pics of your controller with the pot box wires disconnected.