New wiring harness difficulty

[Matt69olds]

can you hear or feel the relay click when pushing the horn button?

Find the heavy dark green wire coming out of the firewall connector. Check for power on it when pushing the horn button. If you have power, go to your nearest salvage yard and get a couple horns off a late model Cadillac or other big car. Don’t get horns off a small car, big trucks need horns with AUTHORITY! Keep in mind, there are 2 horns with different tones. Most are A and F. Be sure to get whatever plug fits the horns.

You might need to get creative with mounting the horns under the hood. Once mounted, wire them up. Late model horns have a ground wire, the factory horns grounded thru the mounting bracket.

I used horns of a late 90s Fleetwood on my 81 GMC. They fit well and are loud.

 

[Fjordlander]

can you hear or feel the relay click when pushing the horn button?

Find the heavy dark green wire coming out of the firewall connector. Check for power on it when pushing the horn button. If you have power, go to your nearest salvage yard and get a couple horns off a late model Cadillac or other big car. Don’t get horns off a small car, big trucks need horns with AUTHORITY! Keep in mind, there are 2 horns with different tones. Most are A and F. Be sure to get whatever plug fits the horns.

You might need to get creative with mounting the horns under the hood. Once mounted, wire them up. Late model horns have a ground wire, the factory horns grounded thru the mounting bracket.

I used horns of a late 90s Fleetwood on my 81 GMC. They fit well and are loud.

The horn button doesn't work. I removed it and found it was broken and the PO just glued it in place for show.
I'll look for that heavy green wire. At this point I'd be happy with a separate horn button on the dash so if I can find the correct wires I'll be happy

 

[hip2bsquare]

agree for purchasing a multi-meter, a descent one at a "big box" store should be good. also if you really want to begin to learn then find a PDF version of your year model truck's wiring harness(s). I recently completed a LS Swap in my '86 and had very limited knowledge of wiring, but if I can follow a wiring diagram I am sure you can & it is very helpful. there is probably a member here that has them or you can check other sites for them. PM me & I can give you a site that has them (if desired).
good luck & please keep posting the results.

 

[Gilmore]

If you’re going to attempt it spend the extra money and get a painless harness. It comes with a book that takes you through it step by step. But before you begin read the book cover to cover.

 

[Dan Brown]

First thing you need to do is get on the internet, i. e., Google and find a wiring schematic for the entire truck. You will probably get lots and lots of hits. Then watch lots of YouTube videos. You'll find plenty of them. Watch them, buy some electrical testing equipment, and go to work. If you get into making harness like I'm doing for the 1974 K10 I'm restoring, do the best job you can using the best components and wire from the internet. Something else I've done on my K10 project is reuse some of the existing harnesses. Make sure they are in good useable shape, clean the wire and terminals up real good, and they should do fine. Chevy knew what they were doing. Good luck and give her hell.

 

[jrico]

Just hopping in here, if there is a more relevant thread let me know. But here it goes, I have an 86 c10 first year of computer system control. Well PO yanked 700R4 and dropped in TH400, swapped HEI to an older model. So I am left with ton's of extra wires in the engine compartment. Like many lots of splices ect.

Was thinking of switching to an older harness, or just cutting out anything not connected. Future plans are probably just running a 350 and th400, would like AC eventully.. Anyone suggestions - or if this is covered in another post I am happy to jump to it.

Also I have had not good look finding a diagram showing the actual wire harness locations / plugs. My Chiltons is not much help..

 

[Dleslie212]

I'm in the same boat as you with my 77. I bought an entire Painless harness. It's time consuming, especially this time of year when it's too hot to work on it once the sun comes up. But it's not terrible. The Painless manual really comes in clutch. I'm maybe halfway done as of now. If you're handy and patient, you can figure it out

 

[Rick R]

Great to see you trying to learn. I've been working on my sons '73 c10. I went with American Autowire and have been pleased so far. I got the Original Harness's, (headlight to tail, w/A/C) which come with no instructions or diagrams. AAw guys are very good at helping and are easy to get ahold of. Harnesses are built using the original diagrams. All connectors are in the right location and the routing is as original. I'm hoping to power up (and firing up the 350 I rebuilt) this week. I'm praying all goes well.
Go online and download the needed diagrams. Books are available and helpful. It made my build so much easier (I hope). You can get so much info here and YouTube. Do get a decent meter and learn to use it. Troubleshooting is a PITA but rewarding too. It is more difficult without diagrams. The guys on here seem to be very knowledgeable and helpful.

Happy Trails.

 

[etc86]

I truly wish you luck in your endeavours. Thankfully this site is full of people that know heaps and are actually happy to share. Also, YouTube. It’s pretty handy for most things these days. My horn is currently not working but that’s only because I had to delete it when I changed steering wheels. PO had rigged up a temporary fix out of a nail, part of a pen and a piece of rubber that worked for the original but made my horn go off when I turned the wheel. Maybe I should have tried the one they made out of electrical wire and a .22 casing?

 

[etc86]

Also, I need to get an auto-electrician to look over mine from front to back, due to the motor and trans being out of an npr there are things disconnected all over the place that I’m not certain are meant to be. Thankfully it runs but it would be nice if it was a bit cleaner.