91 36v ezgo wont go

deerhunter

New Member
Hi, new to the site and to golf carts. I bought a 91 ezgo put new batteries in it. It ran good in reverse but in forward it would only run if the pedal was slightly pressed. Then it stopped completely. 37.8 pack volts. I can hear the solenoid clicking (just once not all the time). On the batt. side of the solenoid it has 37.8 volts and controller side it has 21 until you press the pedal then it goes to 37.8. The orange wire coming from the micro switch on the pedal assembly has 37.8 but, in between the orange and black wire which goes to the controller is a diode or resistor (orange wire side has 37.8 black wire side has nothing). Also, I have checked the potentiometer a the pedal and it has 0-5000 ohms as it should. Am I right to think that the diode is the problem. Don't know where to go from here. Any help would be appreciated. Thanks, Brandon
 

fabbinman

New Member
Welcome to the forum!
welcome.gif


Is it a DCS cart?
 

HotRodCarts

Cartaholic
If your getting full pack voltage on both sides of the solenoid with the go pedal pressed the motor should run if all cables and connections are good.
I'd start with testing the motor.
 

deerhunter

New Member
I checked the voltage at the motor and I think all the cables had 20 something volts until the pedal was pressed the it went to 37.5. Is this common for them to carry some voltage?
 

HotRodCarts

Cartaholic
It sounds like you have more than one problem and that can be hard to figure out over the forum.

First jack the back of the cart up and put it on jack stands. Jump the two large posts on the solenoid then try pushing the pedal and see if the motor runs. Don't let it run wide open. If it runs replace the solenoid. If the cart doesn't run with the solenoid jumped test the motor...

Test the motor while you have the cart jacked up. To test a series wound motor do the following:

Remove the main positive and negative cables form the battery pack...
Spray the 4 studs on the motor with a little penetrating oil...
Mark the cables then remove all four cables from the motor (use a wrench to hold the jam nuts)...
Put a jumper wire from a "A" terminal to an "S" terminal. (Example: A1 to S1)...
Then hook a 12 volt battery or 12 volt battery charger in the 15+ amp range to the remaining "A" and "S" terminal (Example A2 and S2)...

Be careful, if the motor is good the tires are going to spin as soon as you apply the power to the motor. If it doesn't spin it's bad.

If the motor runs doing the motor test I'd say the controller is bad. A bad controller can also cause the strange voltage readings your getting but run all these tests first to be sure...
 

HotRodCarts

Cartaholic
Unless you have a bad connection somewhere I'd say it's definitely the controller.

You can jump B- and M- at the controller to bypass the controller. Make the final connection away from the controller and raise the rear tires off the ground before jumping the controller, it's going to run a wide open throttle.
 

deerhunter

New Member
jumping b- and m- made the rear wheels turn and a big blue spark. Maybe I should have tighten them cables on instead of holding them. Thanks for the info it looks tobe the controller. Thanks Brandon
 

deerhunter

New Member
Took the old controller apart and it was fried it had gotten water in it. Replaced the controller (with a 400amp) and everything is fine. Thanks everyone for their help.
 
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