I have a 2002 gem e825 that’s giving a code 66 and forward mode and a code 57 in reverse mode just got the controller back from flight systems yesterday and it’s still throwing these codes already took the motor out and inspected it fully appearances are that has been recently rebuilt it ohms out within spec.
To further isolate if this is a controller or motor issue, Try disconnecting the F wires going to the motor. If motor, code will change.
Another way to double check is to put this on another car.
Different error codes between Fwd and Rev sure point to the controller tho.
It wouldn’t be the first time things have come back from FSIP still showing errors. (You are not the only one and this is not a new thing).
motor inspected/ohms out within spec.
Did you also check F to case, A to case?
Both field and armature faults suggests ground fault or field to armature short.
Might need to start swapping parts.
Main contactor check out ok?
yup what @Inwo said. And when i got a -66 I’d posted asking if that was something which would damage the controller since it threw the code and cycling power had it working again. I didn’t get a response in a few hours but by then my 2002 GEM threw the code again stopped working. It would only go backwards. I did not find anything visibly wrong with the motor but when I ohmed out the field to the case on the motor I was surprised to get some reading instead of an open circuit. A new controller and new motor fixed the problem.
But the lesson is that if you get a 66 and your motor isn’t replaced or re-evaluated electrically, then you might just blow out some FETs on your controller no matter if it’s old or rebuilt. $0.02