Electrical and Harness Repair Parts

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KingBowzer

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Joshua
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1986
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C10
Engine Size
350
One thing I'm curious about is, it seems that I have an additional positive cable. I have the battery cable, the alternator connector, the eyelet that goes on the back of the alternator, and the line that runs to the starter, but also an additional eyelet piece that looks like it goes onto a stud or bolt or something. As you may notice, I suck at wiring/electrical lol

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AKguy

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Alaska
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Randy
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1981
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K30 Crew Cab Silverado
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460
Wanted: Wiring Harness

Oddly enough it wouldn't let me post this in wanted I would like to buy a complete wiring harness for a 1989 C3500 (Square body crew cab).

I cannot give enough praise to the folks at American Autowire. I used their complete upgrade kit for my daughters 1969 SS 396 Chevelle, and I just received a replacement engine harness for my 80/81 C20 to K30 project. Their products and support are incredible. Yes, they are not inexpensive, but well worth the coin.
 

Scott91370

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Scott
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1985
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Sierra1500
Engine Size
350
Hoping someone might be able to give me a hand....it seems my marking and labeling for wiring harness on my 86 C10 has been washed away during my teardown and rebuild. Truck has been swapped from stock 305 to 350, 700R4(I believe I dont have RPO in front of me) is now a th350. From the fusebox (in the engine bay) how is the wiring harness routed? It runs under the brake booster across the firewall, where does it go from there?

I just did this exact same thing - 305->350 and 350->700r4.
I can take some pics but I actually wasted a lot of time putting all the wires in loom so I don't know how well the pics will turn out. I'll try and get them tonight so you can at least look at them.
 

KingBowzer

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I just did this exact same thing - 305->350 and 350->700r4.
I can take some pics but I actually wasted a lot of time putting all the wires in loom so I don't know how well the pics will turn out. I'll try and get them tonight so you can at least look at them.
I appreciate the response, but i was able to get it figured out luckily. I have it run along the left top ide of the intake, down between the alternator and cylinder head, and from there the starter cable runs beneath the motor mount and the rest runs to the battery. It was a pain in the ass, but it eventually got worked out. Half the problem was me being exhausted and frustrated with this truck lol

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Scott91370

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Glad you got it. It is a pain when you start trying to figure out why some wires are so long and why they were put where you 'think' the factory should have put them.
 

AuroraGirl

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keep in mind mine is definitely not stock, but stuff probably is going generally where it went originally maybe. And if its not, its probably why it has frayed or broken parts to it

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GMDiesel

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Julian
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1984
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K5 Blazer
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6.2L
Hello Everyone,

I'm new here and I may have skimmed through to fast... Anyone got any tips on where I can get a new wiring harness for my glow plugs? I bought a 84 K5 Blazer with a 6.2L diesel that was mickey moused like crazy and I'm thinking about running through and replacing all the wiring.
 

Matt Frediani

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Matt
Truck Year
1987
Truck Model
GMC V2500 Camper Special
Engine Size
TBI 5.7 350
Does anyone make a factory style harness for a 87 gmc v2500 with a TBI 5.7 350? I would like to replace mine.
 

jameshwilson

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Rome, Ga. 30165
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James
Truck Year
1985
Truck Model
C30
Engine Size
6.2 Diesel Convertered to 7.4L Gas
Hi, New to the Forum. I have a 1985 C30 Crew Cab. It was born with a 6.2 Diesel and has been changed over to a 454 Gas Engine. I am trying to clean up the engine Bay. The wiring is a mess. I am putting the wiring in the flex tubing and making repairs to connectors and damaged wires. Unfortunately, I got out here one day, and starting taking things apart. The one time that I did not take before pictures. I cannot figure the correct wiring for the 2-Pin Block on the Firewall and the 3 wire Internal Regulator wiring. There is every video and picture on the internet except the one I need. Could someone out there assist me in getting this truck wired back correctly, with Alternator Charging and guage working, as all was working great before I started. I have something incorrectly wired. Thanks.
 

Scott91370

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...as all was working great before I started. I have something incorrectly wired. Thanks.
Welcome aboard!!! Go here and look at the first two posts, they're stickies so they are at the top.
Wiring diagrams and service manuals - they will help tons!!

 

84GMCSierra

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Paul
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1984
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C2500
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That's a great site. There's some pieces on there I need. Thanks for posting it.
 

Raider L

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1974
Truck Model
C10
Engine Size
355
The other day i used a little air compressor I bought you plug into your cigarette lighter, okay? (That means there's a story of a screw up coming.) I couldn't get the end onto the valve on the inner tube to use it although I did turn it on for a few seconds about three times then gave up. After buying the compressor I noticed at the bottom of the instruction sheet it read, "Warning do not use with the old 3 amp. cigarette lighter but use with the 8 amp. power point for power." Yep, I knew that and had used the old one like this one I just bought for years with no problem until it wore out.
So I figured, "Yeah I see those instructions I'm supposed to use it with a heavier power point socket but it'll only take a minute. Besides I used that other one for years and nothing ever happened.", so what the heck, right? Yeah, famous last words.
After i stopped using it everything was fine until I got home later and for got to run an errand and cranked the truck up again. I got about a block and a half and smoke stated coming out from under the dash. I stopped without turning the truck off to look under the dash in hopes of seeing what the heck the smoke was coming from. In the process I grabbed the wiring going up to the ignition switch and it was hot but that's not where the smoke was coming from.
I raced home and parked. Later I got under the dash to see if I could see what had happened. Sure enough I discovered the Alt. signal wire had apparently fried melting itself into the wires it was tied to and slightly melted some of them together.
I got the schematic out to figure out what I had done and what i discovered, and maybe some of you would be able to straighten me out on some of the details but when I pluged that pump into the cigarette lighter, which is that #16(?) orange wire fed 12 volts all the time goes directly to the ignition switch and back to the fuse block. None of the fuses were blown but the draw from tjhat pump must have burned that alt. signal wire but not bad enough to keep me from leaving from where I was at using that puimp. But the next time I cranked the truck, that signal wire got melted to the orange wire it shares in the ignition switch plug, same hole, and fed 12 volts into the alt. signal wire. And since that signal wire only carries 12 volts in it until the alternator field is energized then is disconnected through the voltage regulator, suddenly had 12 volts on it all the time and caught fire. Man that thing was fried from one end of it to the other. but thank God it only slightly stuck itself to some of the other wires and I was able to clean all that up.

I'll solder another signal wire on tomorrow, But are my findings about what happened about right?
 

Raider L

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KingBowzer@
When i rebuilt my '74 C10 i looked at all that wire running across the top of the engine going to the starter and thought, " Man, there has to be a better way!" So I got a piece of fenolic material, made a terminal block out of it with all the appropriate bolts and screws for the ignition wires and battery, starter wires, screwed it to the fire wall next to where the wiring loom runs across the top of the fire wall. Then cut over 5 ft. of excess wiring out of it all that goes to the starter. Like, the starter is right there below the exhaust manifold why go all the way across the top of the engine, then turn under the alternator then go all the way back across the engine under the exhaust manifold then turn down to the starter. Stupid. All I did after attachiung the terminal block was take some of the wiring that I cut out, attached it to the terminal block and dropped straight down to the starter. Put a Adel clamp on the firewall to hold the wire back as it came down near the back of the exhaust manifold and bent it in place at the starter. It is easy to get to whenever I need to detach it from the starter and it's never hanging all over the engine when doing anything else on top of the engine.
 

Raider L

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HotRodPC@
I went on that sight for the connectors looking for a tool to take a couple of pins out of the ignition switch plug but all they had were the water tight plug pin extractor. Then i saw a catagory called Packard 56 connector tools and yeah I do have some of those kind in the truck. I made a tool to get those out some time ago with one of those pocket screw drivers ground down real thin and narrow. But I need a tool for the big plugs like go on top of the ignition switch. I had no idea what they are called and I was surprised that those smaller plugs had a name like "Packard". If that's the case what the heck are those big plugs called? I was looking earlier and just typed in " '73-'87 Chevy old big plug wire extractor". I know, funny, huh? I didn't know what else to call them. Then I see that sight called some of them "Packard", like Packard cars? I like Packard's. I guess Packard invented them? So what are the Chevy, and I'm sure Ford, and Chrysler all had the same?
 

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