2008 RXV EZGO brake only releases in tow mode

[David Drum]

I have a 2008 RXV golf cart and the brake won’t release. If I switch it to tow mode, I hear the brake release and the cart rolls. I have 48 volts at the brake connector in tow mode. In run mode, there is no voltage. I’ve checked the brake switch at the pedal, I’ve disconnected the 10-gage wire at the controller and that didn’t work. I’ve wiggled all of the wires at the 9-pin connector too.

What have I missed?

Thanks!

[cgtech]

Missed putting a handheld diagnostic tool on it, so you would know what area to chase after, as opposed to the shotgun approach.

[jkredman]

RXVs can be sensitive to a number of things. The first question is which controller do you have. The grey one is a Danaher the black one is Curtis. In 2008 the factory EZGO RXV had Danaher controllers. However, they can be replaced with Curtis controllers.

The next step is to find a handheld diagnostic tool. The Danaher tool is hard to come by. The Curtis handheld will provide some very limited info on a Danaher controller, but is much easier to come by.

Assuming you’ve got a Danaher you probably need to latch on to a service manual with the diagnostic process and a digital multimeter.

My limited education guess, (based only on all the problems I had converting my 2010 cart from Danaher to Curtis, is that there is some power on diagnostic that is failing and the controller is refusing to release the motor brake. My experience is the Danaher was far more tolerant. In my case the Curtis disliked multiple things about my cart and I had to go step by step to deal with the different issues.

Finally, don’t let this scare you. I got a really good deal on a 2010 with a Danaher controller that I tricked out. Then deciding I wanted to upgrade to the 350 Amp version of the Curtis controller; I broke my cart and then had to make the new Curtis controller happy again.

[David Drum]

I looked and the controller is dark grey, and is labeled ACD Motor Controller. I will call around tomorrow to see if any local shops have a diagnostic tester. Thanks for the replies!

[BobBoyce]

Originally Posted by David Drum

I looked and the controller is dark grey, and is labeled ACD Motor Controller. I will call around tomorrow to see if any local shops have a diagnostic tester. Thanks for the replies!

That is a Danaher controller. You'll need to let the shop know which controller you have. The Curtis version of the handset cannot communicate with the Danaher controller at all, the communication ports are not compatible. The Danaher RXV uses a CAN Bus, the Curtis RXV uses a 3.3V logic level inverted Enhanced Serial Bus.

[David Drum]

I finally found a shop with a diagnostic tool. It turns out the problem was the speed sensor in the motor, which is embedded in the bearing. $525 later, I am running again.

[BobBoyce]