Electrical problem...I'm stumped

[coinball]

Got in this morning waited for the glows to go off and turned the key to start - click and completely dead dash. To be more specific everything on the interior harness was dead (my manual GP relay pulls its switch power from the distribution block on the drivers floor to the left of the brake pedal). Screwed around for awhile with the multimeter, cleaned the grounds, cleaned the battery terminals (I'm using top mount not the stupid side mount), getting 12.5V off of 2 optima red tops at the fuse block under the hood.

So I figured I was a victim of the dead ignition switch, so I blew $160 on one at advance auto parts (AC Delco brand). Hooked it up, dash was operating fine, figured that was the ticket. So when it's all done and I go to crank the engine over, I get the same as earlier in the day - click and dead dash. Cycle key off/on doesn't make a difference, dash is dead (as is everything on the interior harness). The only thing showing a sign of having power is the gear selector indicator under the speedo, it lights up orange...not sure why that's happening.

Could the starter have gotten fubar'd causing an internal short or something that drains everything?

I have no wiring diagrams, so I'm fairly limited in my ability to trace wires at this point...

Anyway, if someone wants a killer deal on my Tahoe, feel free to pm me...it's time for it to go

[MrDiesel]

I had the same problem with my truck. Try Replacing your ground cables from the batteries to the motor. My batteries are combination stud and side mounts so i just took the chance to convert over to stud mounts. A simple way to test is to parallel the grounds with a set of jumper cables. If everything works you found your problem. Funny thing was my old ground cables where tight and didnt show any signs of breakage inside the insulation.

[97-6.5TD-F]

The 95 and up ignition switch system uses a plastic rack and gear off the ignition tumbler which actuates the switch itself. Sounds like it is worn, and now doesent engauge the switch completley. When you could still start it did you have to turn the key all the way to the lock position before it shut the engine off? That problem is common but I havent seen it not start the engine beofre, but you never know.