I have a GMC Sierra with a Th400/t-brake in it that I obviously now shift via a RMVB. I want to hook up some sort of shift light, but I don't want a bulky tube shaped light sitting on my a-pillar or steering column.

I'm wondering if I could use the signal the PCM sends to the 1-2 and 2-3 shift solenoids to light up some little LED lights. I still have the harness for the 4L60E, and as far as I understand it, the PCM is still commanding the soleniods even though they're not being used.

I think all I would have to do is make sure that all tables are tweaked to ensure that regardless of load, map, or line pressure it tells it to shift at XXXXrpm.

Does this sound like it might work, or am I crazy?