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Argh! Need a clue...

Revhendo

Revhendo

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Hey, anybody got a wiring diagram or a link to one for a 76 GMC Sierra? Got a little power issue (truck's issue, not mine) going on. Got power in the engine compartment all the way to the bulkhead but nothing inside. Headlights, dome light, dash, ignition, nada. I'm thinking the ignition switch, I pulled the bulkhead and fuse panel, it all looks good. I just need to know if it all goes through the switch and then out to everything.
 
Well do you have an amp guage or a dc volts guage?...I could think if you amp guage is dead you probably smoked it..that's how the old Dodge's do it anyways.
 
Yeah, thought of that. GMC works a bit different than Mother Mopar. (Cut my teeth wiring M880's for Uncle Sam). Kermit the truck has a factory volt gauge. I pulled the fuse panel and the main power wire goes from the bulkhead up to the ignition switch. The swith is cheap enough, just don't need to take ol rusty out to the store and get stuck.
 
Rev yes it all goes through the ignition switch under the dash on the column. Not to bad to put one on but it is award because you will need to drop the column. One dropped put the new one on and adjust it so the rod will work properly. The first time I put one in It didn't work becaus like a dummy I forgot to adjust it. I hope this helps

Cliff
 
Thanks Cliff, definately the info I was looking for. It's kinda what I was thinking. Got half my dash pulled apart to fix a couple of other things while I'm at it. (Can't just leave crap alone.) I've done other GM column mounted switches before, but man did they go out of their way to bury the one in this truck.
 
Revhendo said:
Yeah, thought of that. GMC works a bit different than Mother Mopar. (Cut my teeth wiring M880's for Uncle Sam). Kermit the truck has a factory volt gauge. I pulled the fuse panel and the main power wire goes from the bulkhead up to the ignition switch. The swith is cheap enough, just don't need to take ol rusty out to the store and get stuck.
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So for my daily learning experience how is the fuse box powered up...WAG to the ignition and they fed to the fuse box?
 
The sad part is, I actually bought a wiring diagram for the truck when I got it. It's in my garage somewhere. Got packed when I moved here a couple years back. I'll find it eventually. But yes, the power goes through the bulkhead to the ignition switch (pretty standard GM practice) then to the fuse panel. I'm just a bit foggy on the rest of the circuits on this model.
 
Revhendo said:
Thanks Cliff, definately the info I was looking for. It's kinda what I was thinking. Got half my dash pulled apart to fix a couple of other things while I'm at it. (Can't just leave crap alone.) I've done other GM column mounted switches before, but man did they go out of their way to bury the one in this truck.
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Good luck with it. I have a 83 G20 Conversion Van Company who did it is unknown. I hate to say it if this gone gets electrical problems which they all do this one will go to the scrapper.
 
My s-10's steering column was a nightmare. I wound up just swaping it out for a new one and never had anymore problems. Ya, the older columns like yours are all kinds of wierd lol howdy Cliff!
 
LOL, the best part is. I'm a factory trained Chrysler tech who works in a mainly Chevy restoration shop. You would think I would know better (or at least more).
 
85Rusty said:
My s-10's steering column was a nightmare. I wound up just swaping it out for a new one and never had anymore problems. Ya, the older columns like yours are all kinds of wierd lol howdy Cliff!
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Hi ya Chuck Good to see you here.
 
Revhendo said:
LOL, the best part is. I'm a factory trained Chrysler tech who works in a mainly Chevy restoration shop. You would think I would know better (or at least more).
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Uh Oh LOL. Could be worse Rev you could have a memory like mine. :jaw:
 
Well kids, it wasn't the ignition switch. Spent the day putting my dash back together and then rebuilt my engine harness. For the moment I'm going with some really corroded factory crimps at the fusible links and the alternator power splice as the problem. The miss in my diagnosis was the fact I had power at the bulkhead when I tested it, but inside when I hit the switch, I had zip. (I ran with that assumption and didn't go back out and test the powerblock or bulkhead again). Just tossing it out there for whatever info you fine folks can gleen from my journey.
 
Don't you love it when it turns out to be something easier than what you start with?!
 
LOL, yeah, could've done without the whole pulling the engine harness out and rebuilding it (no crimp connectors) for a Saturday deal. I upped the wiring gauge on all the power circuits and threw in some better protection for all the connections. It's all solder, shrink tube and tape. Lotta love for a truck I got for free. All I had to do was throw in an engine I had lying around and I've driven it for over eight years now. I don't mind giving back every now and again.
 
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