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?