Bachmann Spectrum SD45
Photos and text submitted by Jim Fuhrman of Garden
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.