Yes, I have. I put a digital volt meter on the battery, turn th unit on and it goes thru a test come on, I step on the floor pedal and the brake releases, I move the handle very slowly and the forwar contactor pulls in as i slowly increase the throttle my battery voltage starts dropping (no movement) when the voltage drops to about 6 volts then the pmt kick out and I get the code 57, does the same thing in reverse, does that tell you anything?

Symptom
Forward or reverse contactors open and close, then can
only be closed by opening and closing the key switch.

Possible Causes
Reversed yellow and green current senors wires
- Insure that the:
- green wire connects to PZ4 with
no open circuits.
- yellow wire connects to PZ3 with
no open circuits or loose connections

Reversed power cable connection.
- Insure that the battery negative cable connects to
SCR NEG and the motor A2 cable connects to SCR
A2

I'm sure you have already checked this?

Thanks for your response, I did have a battery issue so we actually put a newly refurbed battery in the unit, thought that would do it but still code 57. I did check the motor field to ground and is ok. Aslo checked polarity on sensor, okay and polarity on pos/neg is correct. I'm really stumped.

the motor is a possibility
check the cables and the motor itself, ohm it out for field shorts to the frame. Also check the battery to frame grounds.
code 57 is a current sensor issue and if the field is grounded to the frame and battery has grounds to frame through case it could be picking that up as a cross polarity problem.