Hi!
AFAIK is the GP40 similar to GP50 and U-23B. There's no wiring whatsoever, simply pull the shell, unscrew the two body screws, lift off the upper body halve, turn the motor 180° and place it back in the body, so the two motor contacts meet their contact points again. Carefully set the trucks in and keep an eye on the two semi-circle brass contacts outside the body slots and the plastic spacers between body halves. Push the lamps back in and that was it.
The loco will now run in correct direction.
With a little skill in tinkering the most of this is self-explanatory while working on it.
Regards
Mathi
AFAIK is the GP40 similar to GP50 and U-23B. There's no wiring whatsoever, simply pull the shell, unscrew the two body screws, lift off the upper body halve, turn the motor 180° and place it back in the body, so the two motor contacts meet their contact points again. Carefully set the trucks in and keep an eye on the two semi-circle brass contacts outside the body slots and the plastic spacers between body halves. Push the lamps back in and that was it.
The loco will now run in correct direction.
With a little skill in tinkering the most of this is self-explanatory while working on it.
Regards
Mathi