2001 Ezgo shuts off after 30min of driving

[shibby]

Hello guys I’m new here and just recently bought a 2001 36v ezgo txt. It is lifted with 23inch tires the guy I bought it from put brand new batteries in it, a new heavy duty forward reverse switch, heavy duty solenoid, and a new controller.

The problem I am having is after driving the cart around the neighborhood for 30 minutes or so it will stop running and you will not hear the solenoid click. After letting it sit for a few minutes and turning it off and on it will start running again then after awhile it will shut off again and there will be no solenoid click again. And so on. I’m not sure where to start since just about everything is new. The solenoid seemed the be the hottest out of everything about 115. I was thinking maybe the speed controller isn’t big enough and it was overheating and shutting down but it didn’t seem to be very hot it was about 95 degrees.

Any help would be greatly appreciated and thank you for taking your time reading my post!

[JohnnieB]

Sure sounds like the controller is going into over-temperature shutdown.

Your suspicion about not having a big enough controller for the 23" tires may be correct. What is make/model of controller?

Check the temperature of the controllers terminals. The M- buss is typically used to heatsink the MOSFETs and its temperature used to trigger the over heating flag.

[shibby]

Thanks for the reply. It looks like the controller is a golframa G633 25864G0X. It looks like it’s a 350 amp controller. How hot should the M- terminal get before it’s considered overheating?

[JohnnieB]

The controller you have is a Curtis 1206 whose 275A throughput MOSFETs have been replaced with 350A throughput MOSFETs and still in a case designed to dissipate the heat produced by a 275A throughput.

I also suspect the non-reusable thermal pad between the controller and heatsink was reused.

Toss 23" tires into the mix and you've got something approaching a perferct thermal storm.

I don't have any temperature specs on a 1206, but thermal cutoff is probably upwards of 200°F. Problem is the temperature is sensed internally, so measuring at the exposed end of the M- buss will likely be lower than what is being sensed internally.

However, I just realized I missed the fact that the solenoid is not clicking and in a series drive using essentially a stock controller, getting the solenoid to click is entirely external to the controller, so it doesn't matter if the controller is good or bad, the solenoid ought to click when the pedal is pushed.

Attached is a schematic with the solenoid activation circuit highlighted. Take a DVM along on your trips and when the cart misbehaves, check for full battery pack voltage on the wires highlighted in red.

[shibby]

Thank you I’m not entirely sure where all those connectors are but I will give it my best shot. I’m not sure where the pedal box is. I also noticed I do not have the small red wire coming out of the charging receptacle the reed switch I believe is what it’s called. It looks like my small red wire is connect straight to the 36v battery. So no solenoid click makes me think it’s a bad solenoid or the wiring to the solenoid is messed up not the controller?

[JohnnieB]

The pedal box is under the floor mat.

There is a gray cable coming out of the pedal box that has an in-line connector that connects the four wires it contains to the carts wiring harness. That connector is the source of a lot of problems and many people replace it with individual butt-splices or solder joints and waterproof with marine grade (adhesive filled) shrink tubing.

The reed switch is another problem source, but it sounds like the one in your cart has already been bypassed.

[shibby]

Here is a picture of my Controller and solenoid along with my forward reverse switch. Thanks.

[cgtech]

Something looks suspicious on the diode, please confirm.

[shibby]

Yes it looks like the Diode maybe melted at one point. I believe it probably melted with the last solenoid and was just reused. I have read that the Diode isn't even needed so not sure if that would make a big deal. Thanks for your reply.

[JohnnieB]

If the diode lead is touching the metal can of the solenoid, as it appears to be doing in the pictures, that is a problem.

Remove the diode and any melted stuff and try the cart again.

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True, the diode is not needed for the cart to run, but the pedal switch's contacts will last a lot longer when a spike suppression diode is installed.