How do I set an older electronic e-unit to always go forward?

[pittpa1958]

I have a Pennsylvania Loco #4656. The unit was built by Williams Reproductions Limited from Columbia Maryland. It is a Diesel SD-45, Pennsylvania RR. . I want to set the e-unit to always go forward. The old Lionel's have a manual switch but this is a newer electronic e-unit. Can I easily set it for the forward only direction? If I set it to always go forward can it be set back is desired? Once I opened the unit I found that the card is different than I see in the documentation and card image on this forum. It is probably older than I thought or the current cards. The box is labled Williams Electric Trains and stamped PENN RED SD-45 4201 REV
Thanks

[phillyreading]

Does your engine have a small switch underneath on the engine? It can be really small, almost the size of a micro switch if so equipped, and that should allow you to lock it into forward.
The problem that I have encountered with the electronic circuit boards is that they always start in forward, even if set to nuetral.
If no switch, you may have a problem as Williams used at least four differant circuit boards in their engines, you must know which circuit board so that you can proceed with a fix.

Lee F.

[Joe Satnik]

Dear Pitt,

You could brute force wire in a diode bridge and switch(es), depending on which modes you want to switch between. 

You could choose series/parallel, manual fwd/neut/rev, bridge (manual)/reverser board.

Wadda ya want?

Sincerely,

Joe Satnik