Hey so I dug up the wiring diagram for my 1994 Chevy 1/2 ton and it says the tan/black wire on the blue connector is the TCC Solenoid control wire.

I traced it out and it has that little connector on it -- which means this is the wire I disconnect when I want to set base timing.

I searched and sure enough the tan/black wire is what is used to disconnect and set base timing... but again- according to my wiring diagram- this is the TCC Lock control wire.

Anyone know anything about this? Are they a shared function or do I need to find a different diagram?

thanks all.