I need HELP!! Lights switch and ignition??

[dot4x4]

Going off of memory so excuse me if I am wrong.... Plus I am still learning with my own truck...


Stand on the passenger side of the truck looking into the engine compartment. Look down at the starter. There should be the selonoid (bad spelling lol) on top of the starter.

There will be a large wire with two red wires connected to it. Trace those wire back up about 10 inches and there will be small black plastic box. Forward of that box is the actual "Fusible link".

That wire with the fusible link is the one that fried on mine. When I spliced a new fusible link and reconnected it to same large stud the large cable goes to from the starter to the battery I had my lights fixed.

As to the starter problem..... I am still working on that. I think that the small wire coming off the "Three" oclock pole closest to the engine is bad and that is at least part of my problem. If you want better advice go back and look for my post right below this main link. Thats mine and I got a great "walk through" on the wiring from someone.

 

[dot4x4]

http://www.gmsquarebody.com/forum/showthread.php?t=11651

Added a link for simplicity sake and in case anyone else looks up this thread in the future.

 

[paolotvl]

Mine doesn't have the fuse link on that wire...

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[dot4x4]

Follow the large black cable from the Positive down to the starter. Where it connects at the starter their should be a fusible link from their that goes into the wiring harness (and then its just regular wiring). that will eventually lead to the Firewall and ultimately connect Just to the left of the brake vacumm booster. on the other side of the truck.


The link is actually on the starter itself. But looking at that pic it seems you have some "Custom" wiring from a previous ownder.

AS I SAID EARLIER.... I AM GOING BY MEMORY AS I AM AT WORK.... and I am still learning myself.

I had to really search for the fusible link on mine as it had fried completely off and was against the fender liner and frame.

 

[paolotvl]

I just noticed that when it is acting out and there are no lights the dash instruments have power but the Orange service engine light is not lighted up while when everything works that light is on


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[paolotvl]

Guys, I just checked with voltmeter the wires going to the light switch. None of the wire is hot...


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[350runner]

"Fuse link"

Sent from the dust in front of you!

 

[dot4x4]

See if I did this right....

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The two smaller red wires on the large "Pole" (top) with the black wire are what we mean when we say the "Fuse link or Fusible link".

One or both, (Can't remember) supply power to the light switch harness.

 

[dot4x4]

well that looks like I did it right, at least I can see it on my work computer...


Editted to add: that picture is just one I found in an image search.... NOT my own pic.

 

[paolotvl]

Ok, we (a friend came to help me) think we found it and when my friend wiggles those wires the cabin light flickers... What do we need to do now??


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[paolotvl]

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Is this the problem??


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[89Suburban]

Is that a pic of your actual wires? That one looks ugly! Where does that wire go? Looks like it doesn't follow the rest of the wires up.

 

[Boone83K10]

Yes, i know...

This is pretty bad... I raised the carpet and there are some lose wires, and everything is wet...

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The only wire you should be concerned about is the ones with the wire nut. The others are normal.

 

[89Suburban]

Mine doesn't have the fuse link on that wire...

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I would move that smaller ground wire going to the base of the overflow tank to the radiator support. Grind a spot clean and bolt it on tight with a knurled washer if you have one.

That alternator charge output wire looks shady too. Should be a large gauge wire and it should run directly to the junction block on the firewall. Setup the way you have it in that pic forces all the strain of the electrical system to go from battery to starter to junction block. Running the alt charge wire directly to the junction block allows the alternator to adjust to the electrical system loads as needed and lets the battery be a backup power feed.

 

[paolotvl]

Ok, first and foremost, thanks to all of you for helping me. Without your help it would have taken me weeks to figure out what the problem was. I really appreciate it.
We realized that the junction box on the top of the firewall, right behind the air filter was not hot. We followed the red wire down to the starter and noticed that the three large wire were all covered and patched with electrician tape and heat shrinking tube, it was very messy. Moving those three wires caused the courtesy light to flicker. One of the two orange wires was all melted/brittle and had almost no section. There was almost no material left so when you turned the lights on it would get very hot. We got rid of the tape and shrink tube and just by doing that, the wire broke. There was only half an inch of wire left, it was already dark so I decided to just patch it. We soldered a 5" piece of 10 gauge wire. Problem gone and courtesy and cargo lights are WAY brighter now. Basically the positive wire powering the fuse box/light switch was way too thin. When you turned the lights on it was overheating and probably somehow (this is still to be explained) either interrupt the circuit or affecting the ECM somehow. In any case, the engine would crank but not fire.
Now, it seems to me that replacing the whole wire must be a very difficult job. If it is not too difficult I might go ahead and replace it, which is what I need to do. At the moment the fix is just a patch, a good patch, but just a patch. I am also going to buy the headlight circuit upgrade do that the lights won't get the juice from that wire. Again, thank you everybody for all the help, it really made a huge difference!!!