[bigmoe]

Originally Posted by dayj1

I've done what you're asking on a 4.8/4l60E swap into a Jeep YJ. Unfortunately, I didn't keep a schematic of what I built. Basically, the trans mounted PRNDL switch grounds one or more of four outputs that are referenced as A, B, C, and P in the GM wiring diagrams. Use a voltage meter to make a chart of which wire(s) are grounded in each gear. You'll find that 3 of 4 lines are all you'll need to represent the 7 gear positions (P,R,N,D,3,2,1). Then you just need to use a network of diodes (or a single IC) to build a circuit to control LEDs (or one of the Lokar LED gear indicators). Google 3 to 8 decoder to see some examples of the circuit you'll need.

This thread shows something similar (posts #35 and #39):
https://www.67-72chevytrucks.com/vbo...=725451&page=2

It's not a particularly easy thing to do if you're not handy with a soldering iron and building your own circuits. I think Dakota Digital (and probably others) sell decoders for this sort of thing but they're definitely not as cheap as using the stock switch.

Thanks Dayj1! Just what I needed to know.