Electric EZGO decides not to run

[barcloverranch]

Hey fellas,

Having trouble with my electric cart deciding it intermittently doesn't want to run. It's an 86 ezgo that I put the cartsunlimited conversion kit in a couple years ago. The conversion kit worked great, very happy with the results. Less than two years ago I put a whole new battery pack in it.

So here's the problem. When it decides it doesn't want to drive I will press the pedal and the solenoid will click, but the cart wont move. Battery pack is reading 38.2v.

So I put a dmm to it:
I am getting 38.1v to the first large post of solenoid at all times.
38.1v to the second large solenoid post with pedal pressed.
38.1v between the two small posts of solenoid with pedal pressed.
38.1v to the #1 pin on the controller with the pedal pressed.

I am not a tech savvy person at all, so if anyone would be willing to offer up the next thing I should test in simple terms I would surely appreciate it!

Thanks guys

[JohnnieB]

Solenoid is clicking and you are getting full pack voltage on the controller side large terminal, so the problem is in the high current circuit.

Connect your DVM between the controller's B- and M- terminals.
You should get full battery pack voltage (38.1V) when the pedal is pushed just far enough to make the solenoid click.

If you don't, there is an open somewhere in the high current cables, F/R switch, or motor.

Leave the negative test lead attached to the B- terminal and go looking go the voltage with the positive test lead. the problem will be between the last spot with no voltage and the first spot with voltage.

[barcloverranch]

Thanks for the quick reply Johnnieb,
Okay so I do get a full load between the B- and M- on the controller with pedal pushed.
Sorry, but I dont understand where you're saying to follow next?

[JohnnieB]

Originally Posted by barcloverranch

Thanks for the quick reply Johnnieb,
Okay so I do get a full load between the B- and M- on the controller with pedal pushed.
Sorry, but I dont understand where you're saying to follow next?

If by "full load" you mean you are getting full battery pack voltage between B- and M- when pedal is pushed just far enough for solenoid to click, what follows in my previous post does not apply.

Next step in your case is to push the pedal further and the voltage between B- and M- ought to decrease to zero as pedal reaches floor.

If it doesn't, the problem is either the throttle input to the controller is bad, or the controller is bad.

IIRC, the conversion kit has a pot-box throttle, so disconnect the black ans white wires that connect to the push on terminals on top of the controller and measure between the disconnected wires with an Ohmmeter.
When the pedal is up, you should get about 0Ω and when you slowly push pedal to floor, the reading should smoothly climb to about 5,000Ω.

If it doesn't, chances are the controller is bad.

However, verify that you get pack voltage on the third small wire to the controller. That is what powers up the controller on and if the controller isn't turned on, it will have the same symptoms as a bad controller.

BTW: it is a good idea to lift the rear tires off the ground and put on jackstands, so the cart doesn't take off unexpectedly and run over someone of something.

Also, I'd verify the motor runs. You can move the cable on the M- terminal over to the B- terminal, ending up with moth the M- cable and the B- cable on the B- terminal, which bypasses controller and throttle. When the pedal is pushed far enough to make the solenoid click, the motor will connected directly to the battery and run wide open until pedal is released. so be careful.

[barcloverranch]

Okay, I went and put it on jack stands to start these tests and it has decided to start turning the tires again. I guess I will wait for it to inevitably quit working again so these tests will actually mean something. I'll let you know as soon as I do. Thanks Johnnie

[scottyb]

Johnnie is asking you to check the controller output andf thats good but this could also be an F&R contact problem. Next time it does not run just push the pedal very slightly to where the cart would usually just start to go and roughly shift the F&R. Be prepared to take off suddenly.

[barcloverranch]

10-4 boss, will do. I just took it off the jack stands and ran it around the block about a dozen times and I can't get the dang thing to fail again. I'll throw it on the charger overnight and see if it'll fail again tomorrow.

I haven't changed anything so somethings still messed up, but just not showing itself now.
Thanks for the help guys

[barcloverranch]

Well for those concerned/experiencing similar issues, I think Scottyb was right. I've made the mistake of using wd40 on the contacts of the F&R switch instead of the main bolt/pivot point and that must have been making for a bad connection. After working that loose and roughly switching several times haven't had any issues.
Today I drove it from home to the golf course (about 1.5 miles), played a round, and drove home, no problems. Thanks for the help everyone!

[Clemsoncartguy]

Maybe the WD attracted some crud or dirt?