Glow Plug off switch

[LCAM-01XA]

That's exactly what I had in mind, but may not have expressed it properly. In my head (Lots of room in there!) I figured I would put the relay between the GP relay's white wire terminal and the white wire itself (Same thing you did)

I am also going to wire myself a high idle switch in the cab. Doing my mod this way, will not interfere with the operation of anything, except the GP relay operation. Did you happen to take any pictures of your mod?

Sorry, no pics of my work, tis all a big wiring mess anyways, lol

When you wire up your high-didle switch make sure you install a diode in the circuit to isolate it from the cold advance so the switch only powers the high idle solenoid - if the cold advance comes on when the engine is nice and hot, interesting things may happen, like for instance a nice little runaway state like mine goes into.