EZ go TXT melted controller

[mark38090]

I have an EZGO TXT 36v cart that is used for work. It has a club car F/R wired in to change the torque for pulling a trailer and reversing contacters but otherwise i don't know of any upgrades.Yesterday it shut off while driving on a straight flat road, the solenoid clicks but nothing happens. I got it back to the shop and discovered the corner of the controller is melted, the cable that connects to that lug looks damaged as well as both cables running to and from the solenoid. The shop that used to do all the work on our cart went out of business so we don't have anyone that will work on anything that isn't stock or upgraded by them so I kinda stuck. What would cause this much heat to be generated and where should I start troubleshooting?
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[Cartmaster]

Looks like a corroded high resistance cable connection has caused the heat and melted the casing of the controller rather than the controller going bad but maybe the higher current drawn has taken the controller out anyway!

I could be wrong here so wait for the experts, i am more of a gas guy to be honest.

Im curious as to how that switch increases torque though. I have only seen switches that alter the motor field for more speed?

[mark38090]

Originally Posted by Cartmaster

Looks like a corroded high resistance cable connection has caused the heat and melted the casing of the controller rather than the controller going bad but maybe the higher current drawn has taken the controller out anyway!

I could be wrong here so wait for the experts, i am more of a gas guy to be honest.

Im curious as to how that switch increases torque though. I have only seen switches that alter the motor field for more speed?

That may be what it does??? I'm not really sure exactly but it has a setting for Torque/Speed on the switch.

[JohnnieB]

Suspect the cart has an EMP 2-speed motor installed. They use a CC F/R switch for an on-the-fly mode selector.

https://empinc.biz/faq/directions-fo...-5-x-sf-models


Replace the controller with an Alltrax SR48500 and replace the all the thick cables with 2Ga.

https://www.cartsunlimited.net/alltrax-sr-series--.html

[mark38090]

Should I replace the solenoid too since that seems to be where the heat was the worst? Is there anything else that could cause this type of heat that could damage the new controller once it is installed? I would hate to spend $600+ and then have a repeat and burn up the new controller.

[JohnnieB]

Originally Posted by mark38090

Should I replace the solenoid too since that seems to be where the heat was the worst? Is there anything else that could cause this type of heat that could damage the new controller once it is installed? I would hate to spend $600+ and then have a repeat and burn up the new controller.

The solenoid is probably okay, but it is a 200A rated model and I'd probable go with a 400A model (MJZ400)

The heat problem was the corrosion impregnated cable conductor and dirty connection. Use high quality cables (all of them) and keep the cable connections clean.

The cables in my cart are made from 600 strand welding cable with soldered on closed end ring terminals that are waterproofed with Marine grade (adhesive filed) shrink tubing. I got them here: https://www.cartsunlimited.net/battery-cables.html over 10 years ago and they are still in good shape.