MPT800 (Series) nogo. Alltrax recommendation?

[Kalenth]

Good evening all.

I have what I think is a 2007 36V EZ-Go MPT 800 . The serial number search on the checker site gives me no results.

I've gone through all the stickys for diagnostics and troubleshooting, cleaned the contacts, checked the batteries, jiggled wires and checked the contacts again... and I'm assuming that my Speed Controller (25864G09) is the problem.

Can anyone recommend the model of ALLTRAX controller that I need to replace this thing? It's pushing a 73445G01 36-48v motor.

[kgsc]

If you just want to replace what you have an Alltrax SR would work.. You sure yours is bad? Solenoid click ?

[Kalenth]

Solenoid does click. I was hoping that the unit wasn't bad. I disassembled it and took a look for circuit board burn or any smell of something fried... no luck.

[kgsc]

Put your volt meter on b- and m- and check for voltage through the range of the go pedal. Should sweep through to pack voltage.

[Kalenth]

When I Connect (-) probe to M- terminal.
Connect (+) probe to B+ terminal.
The reading should indicate approx. 0 volts, mine is reading 0.56.

Pedal start: 0.35 Pedal fully pressed 0.00.

[JohnnieB]

Originally Posted by Kalenth

When I Connect (-) probe to M- terminal.
Connect (+) probe to B+ terminal.
The reading should indicate approx. 0 volts, mine is reading 0.56.

Pedal start: 0.35 Pedal fully pressed 0.00.

M- to B+ ought to read close to 0V when pedal is pushed just far enough to make solenoid click and read full battery pack voltage when pedal is pushed to floor.

A more definitive test is going from B- to M- since only the MOSFETs inside the controller are between those two points while going from M- to B+ includes just about everything in the high current circuit except the MOSFETs. (The voltage reading will be the opposite - Pack voltage when solenoid clicks and 0V when pedal is on floor)

Connect the DVM negative lead to the controller's B- terminal and go looking for the missing voltage.

The F/R switch is the most likely suspect.

[Kalenth]

Good call. Removed the F/R switch. One of the brass lugs has shorted on something. There was built up melted plastic, and no contact. Took it apart and cleaned it, adjusted the lug, got it working.

I also had to replace the PDS. Unsure what the issue was with my original, but once replaced, the cart is up again.

Thank ya’ll for the tips.