Wondered if you ever got this truck going,am having the same issue with a NPR15,wondered what you found?
Line Contactor does not close.
POSSIBLE CAUSE
*Defective capacitor.
- Check capacitor bank per component checking section.
- Check for loose or open connections in capacitor circuit.
*Misadjusted / defective steer interlock switch.
- Check to insure that the steer interlock switch closes after
the line contactoh power tips close. Repair or replace.
-Defective steer control.
- Disconnect the positive cable and 4PL plug from the steer
control. If status code disappears, repair steer control.
-Open circuit in capacitor precharge circuit.
- Check for loose connection or broken wire (WHT) at #3 REC
heat sink or along the length of the wire.
- Check for loose or corroded connection at terminal PZ14.
- Check for loose connection or broken wire (BLACK) at 1 FU
power fuse or along the length of the wire.
- Check for loose or corroded connection at terminal PBl.
*Unsuppressed voltage spikes.
- Check that any and all coils, including horns, that are
present on the truck have the proper voltage suppression.
- Check that the static drag chain is present on the truck and
dragging on the floor so that it keeps static electricity
from building up in the truck.
This is for code 51. The 6 code could be an issue with the travel transducer being out of adjustment.