EZGO TXT Slows when accelerating

[afdude08]

Newbie here. I have a Model E299, 40 volt (2-8volt, 4-6volt) EZGO Txt golf cart with brand new batteries (US Battery) that I got from a guy that sells golf carts for a living. This golf cart has a lift kit with 18" tires. When I press the gas to the floor on the highway, it will fly for about 2 minutes. Then it will slowly start slowing down until it creeps. I replaced my old set of 36 volt batteries because I thought that the batteries were causing this issue. Now I know that was not the case because I am still having this exact problem. I have no idea where to begin testing this golf cart to fix this speed error. Any help in the right direction would be greatly appreciated.

[kgsc]

Depends on the controller but it is probably overheating at 40 volts if it was made for 36. This a series or does it have a run/tow switch?

[afdude08]

it has a run-tow switch. I forgot to add that once the golf cart finally stops, I can turn off the key on the golf cart, wait a little while and turn it back on and it will run fine for a little while and do the same thing again. It was doing this exact same thing when i had 36 volt batteries installed.

[kgsc]

Still sounds like thermal shutdown. Check and see if the motor or controller is getting hot.

[afdude08]

Okay I will try that. To check the temperature of the controller how should I go about doing that with it being covered with the Run/tow switch? Also what is a normal temperature range for the motor and the controller with it running for a few minutes?

[kgsc]

Flip it to tow and remove the pack mains. Mark them first. Pull the cover but leave it plugged in. Hook the mains back up and flip it to run. When it dies put your hand near the controller and motor. You should be able to put your hand on it and leave it there for a few seconds.

[afdude08]

Just did this test and both the controller and the motor stayed cold. There was no overheating in them that I could feel with my hand.

[afdude08]

Do you think the ITS and microswitch under the floor mat would have anything to do with this issue?

[kgsc]

ITS maybe but switch either works or it doesn’t. Try putting it in diagnostic mode and see what beeps you get. Key on, neutral to reverse 5 times stopping at neutral. It should beep 1-4 times telling you what chip is in it then may give some more. Drive it and listen for more.

[afdude08]

Okay, I'll test that out today and give an update tonight. Thanks for your help.