'07 RXV 'Motor Temp High'

[nickdalzell1]

Long story short, a guy who works the campground next to our shop owns an older, 2007 EZGO RXV and lately his cart is stopping after less than half a mile (like from office to theatre, which is a walking distance.) and when it happens it shows a code of 'Motor Temp High' on the handheld, despite the actual readings under 'diag realtime' showing a reading of 33-37 C and a heatsink temp around 27 C.

He has a huge (i mean huge, the thing is ten drawers) high toolbox with more than a half ton of tools (yeah, i tell him he's overloading it and he refuses to listen to reason) so this might have killed a winding or something, but i'd hate to waste putting a motor on it if it's say, a failing controller or something. it's odd that the code is being thrown despite a perfectly normal reading (manual claims it has to be 300 F!!! to throw that code)

all readings at the motor wiring and sensor wiring appear normal. what happens is you go full speed (19MPH) about 200 yards and it sometimes slams the brake on and almost throws you through the windshield, and you can turn the key off/on a few times, or switch it to TOW and back to RUN and it corrects itself. In addition the the heavy toolbox on the rear, it's also got a 6" lift and 20" tires on it

[cgtech]

You can bypass/test the sensor by plugging a ~700 OHM resistor into the harness plug that would normally hook to the motor temp sensor. If you still get motor temp codes with a resistor as a sensor bypass, you know it's not actually the sensor.

[nickdalzell1]

ok, but the sensor is hardwired into the motor, correct? I'm trying to find out if the motor is on its way out or the controller. I've seen codes that point to something obvious (say, encoder fault) but the actual problem is the controller itself.

the reading never seems to go outside normal range leading me to believe the controller is going out. Obviously it's wrong about the temperature (motor won't even get warm and runs fine up until it just randomly stops)

[cgtech]

The motor temp sensor is woven into the motor windings, but it plugs into the harness. I have seen motor temp sensors that only need to heat slightly to all the sudden max-out.

[nickdalzell1]

so does this bypass 'fool' the controller to believe it's normal and all?

[cgtech]

Yep, "temp is normal, and strangely never changes".

[nickdalzell1]

hahaha! If he brings it back i'll try that. Strangely, his cart seems to have 'fixed itself' and we all know how long that lasts. Still can't believe he expects a stock electric RXV to haul not just his weight (he's a big man) but also a 900lb toolbox, as well as a 6" lift kit and 20" tires. The fact he has never rolled it over yet is amazing in itself! He does however go through axles a lot (the axle nuts get loose often and eventually run out of thread to tighten further)