73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Electrical => Topic started by: krystolix on March 26, 2025, 09:44:19 pm
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Back in January I was driving to work. I stopped at a red light and the truck died. I tried starting it and the only thing making noise was the rod in the column to the ignition switch. Nothing from the starter. I still had power to the gauges/radio/blower motor.
Had it towed to the house. It's finally warm enough to start working on it. So far after reading a ton of topics/threads here and other places, also watching videos I'm having NO LUCK.
I've replaced the ignition switch, the ignition key lock, and the neutral safety switch. Still only able to the hear the rod moving in the ignition switch.
Looking around the motor I noticed on the firewall that the junction block had a cable that was maybe burned/melted up. It practically crumbled when I grabbed it. It's a fusible link that connects to two wires (both red 12ga, one to the bulkhead, and the other to the post of the alternator) both wires look good. I had to make two fusible links for that because I'm pretty sure that was an original fusible link from the factory and couldn't find one anywhere to order it. Still could only hear the rod moving in the ignition switch.
I've also found I'm not getting power to the ignition side of my fuse box. Not sure what to do with that (I'm a novice when it comes to fixing vehicles).
My next idea was to make new cables from the starter up to the alternator, and possibly if someone can direct me to where I can learn how to test/maybe replace the purple cable from the "S" post on the start to the bulkhead. I took pictures of those cables from the starter to the alternator but I'm assuming they're too large because I tried making a thread already and nothing loaded up (sorry if this is double post nothing showed on my profile).
But what I'm confused about is when reading schematics and Chilton's/Haynes my truck seems to have more wires on the starter than what others have... One purple to the "S" and that's correct from what I've read, the main post has one from the battery, and then a connection that has three cables (one fusible link to two 12g wires I think, and one single fusible link same 12ga) all red... If I can figure out a way to link photos in a lower resolution I will.
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Here's the starter wires. Any help or ideas of what I can do or look for next would be greatly appreciated.
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Is the key switch actuating the ignition switch? IF not look at the rack and sector actuator. That is the mechanism in the column that moves the rod to fully actuate the ignition switch.
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I'll be looking at that today. Replacing the turn signal switch cause I noticed while replacing the key lock it was cracked.
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So, after installing the new turn signal switch, I inspected the arm and it should be moving enough for the ignition switch. Everything looked good on that end.
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See below...
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One that has two wires from the fusible link, one red goes up to the alternator connector. The alternator connector also has a brown wire that goes to the bulkhead. There's another red wire, probably a 10ga, that runs up to the junction block, and the last red one goes to the bulkhead. All connected at the starter on the bat post. Purple on s post. None on r.
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Do you have an incandescent test light?
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I do have a test light.
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I'm going to ask you to do a few basic tests in a particular order. Do no more than I ask in each step. The process will take longer, but it should minimize introducing wild cards that could complicate diagnosis. Be patient.
Begin with the transmission in Park and the park brake firmly set. Clip your test light to a visibly clean ground and probe the battery cable lug at the starter solenoid (this validates that the test light has a sound ground connection). Next, have an assistant attempt to crank the starter while you probe the "S" terminal on the solenoid. Does the test light illuminate normally bright while attempting to crank?
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Sorry for the break in communication here. I've tested that and it doesn't light up at all.
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I've also tested with a remote push button the bat cable post and s post on the starter. It attempts to start.
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Okay. Crawl under the dash and clip your test light to a clean ground. Validate the test light ground by probing a BAT cavity tap in the fuse box. Now, probe the yellow wire connection to the neutral safety switch at the base of the steering column while attempting to crank the engine with the transmission in park. Does the test light illuminate normally bright while attempting to crank?
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Yellow wire doesn't light up.
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Also doesn't light up on the yellow wire on the ignition switch.
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Ignore that last post. I repositioned the ignition switch on the column. I now have power to the yellow cable.
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So, building off that last post, I pushed the new neutral safety switch clockwise all the way it would go. It now engages the starter! Placing the wires back in the safety tube and gonna try and fire it up.
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It fired up after a few tries, and now driving it! Feels good!
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See what happens when you progress methodically using logic versus frantically firing the parts cannon? Well done! ;)
Just, make sure the engine doesn't crank in any gear positions other than Park and Neutral. Adjust the neutral safety switch accordingly.
With a tilt column, make sure the engine cranks and shuts off at up and down tilt extremes.
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Hahahaha! Yeah
I'll get on to that tomorrow. Thanks everyone!