[VetteVet]

Originally Posted by Resto-Rat

After I fretted over this a while I went back to shop and checked continuity from the light grey wire on the panel to fuse and that is okay.

I then checked continuity from the plug to the panel fuse. Oddly enough all of the plug terminal spades test positive for continuity to fuse panel EXCEPT the dark green. If you mean the light switch plug then you should have continuity to the fuse panel. You might have a problem with the connection on the fuse panel behind the fuse and very rarely the terminal crimp gets the insulation and not the copper wire, which would explain lack of continuity.

Now you said something that the reostat controls. My knob does not spin at all. That may be the problem. Seems like it may be in the switch. I will do as you suggest and jump power to dark green fuse side and test. You may also jump power to the green wire at the light switch plug and the four instrument lights should come on. Make sure that the fuse and the holder is clean and snug.

Should all lights have a reostate and spin. Mine may just be bad. I live in La Grange Texas. Small town in Texas with good NAPA. Is that switch a LMC item or do you think NAPA would have one? There are several suppliers of parts for our trucks and NAPA is one. They also sell off shore stuff just like LMC. I bought a brand new gas tank sender from a place online and I was tickled to death with it if I could just remember their name. They sell most everything for our trucks and the forum venders are very good as well. GMC Pauls has been around here forever.

Thanks for all your help. And got the ac diagram. Very helpful.

I'm glad but I wish I could help more on that issue.