Bachmann Spectrum SD45

Photos and text submitted by Jim Fuhrman of Garden Grove, CA.

First photo below shows installation in which I wired the T1 harness to an uncommitted 8-pin medium plug. The wire leads attached according to the NMRA standard using the pin numbers silk screened on the PC board.  The T1 fits nicely on top of the leads of the rear LED, and no changes were deemed necessary on the PC board.  However, once I had set about to program and test the installation, I discovered that in this configuration, the unit operated long hood forward.

All was not lost, as one of the two units were to operate as a trailing unit anyway, so I wired the second one as shown in the second photo, basically swapping the wires end-for end except for the blue wire.  This configuration of the harness provides for normal short hood forward operation.  I mapped both units to the same address, setting the normal one to have F0 control the head light, F3 to control the headlight of the reverse unit, and F1 to control both rear lights.  In this way I am able to operate them both in a basic consist while independently controlling lights, or operate them individually one at a time if needed.
I also tested setting the lsb of CV29 and swapping the values in CVs 33 and 34 on the reverse-wired unit, which works quite well to flip the operation without the need for rewiring.