Horn problems

[densobro]

horn hasn’t work since I got the truck back in 2020. It’s a 1996 gmc k1500. The horn works when rigged up to a dewalt 20v battery, and is directly plugged in, but when I trace the wires further down, I see another plug close to the fuse box under the hood that isn’t plugged up and I can’t find where the plug would go. Any help would be appreciated. I believe the truck was completely rebuilt and has a lot of things missing and miss matched.

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[densobro]

Also can’t find a wiring diagram that shows this circuit

 

[97Kharon]

Hello there, my 1997 suburban had a similar issues. After removing the grill and battery I was able to fully examine the wiring harness for the horn upon inspection I found the ground wire going below the battery had gotten chewed up and severed the solution was simple I bought a roll of wire that was the exact same guage and reconnected the wires.
The harness runs from the fuse box along side the driver fender and down towards the bumper and across.
However the horns didn’t work lucky I had a Whelen siren system in my storage from my previous truck.

 

[densobro]

Hello there, my 1997 suburban had a similar issues. After removing the grill and battery I was able to fully examine the wiring harness for the horn upon inspection I found the ground wire going below the battery had gotten chewed up and severed the solution was simple I bought a roll of wire that was the exact same guage and reconnected the wires.
The harness runs from the fuse box along side the driver fender and down towards the bumper and across.
However the horns didn’t work lucky I had a Whelen siren system in my storage from my previous truck.

Thanks for the reply and the diagrams. I check the ground wires you’re referring to and remembered I replaced those about 7 months ago back when I had a starter issue. I’m 100% sure my horn issue is due to the plug not being hooked up. The plug has a solid green wire (which goes directly to the horn) and a green wire with a white stripe in it. I can’t for the life of me figure out what it plugs into

 

[97Kharon]

I’m going to my garage shortly, i’ll see if I have a the same connector off the top of my head I don’t recall seeing a connector however there is two horns total one in front of the battery and the other is behind the grill. In my previous reply I attached a troubleshoot guide.

 

[densobro]

I would really appreciate that. I’ve been almost to the point of going to my neighbors house (who I’ve never met, but has the same year truck) and asking them if I could look into their engine bay to see where their plug goes haha. Probably not the best way to introduce myself.
And I followed the steps in the trouble shoot guide and it kept leading me to the same question that I couldn’t answer, I think it was #7

 

[densobro]

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[densobro]

Also when I use a jumper wire like this from the relay ports directly to the plug with no home, the horn works.
But with out the plug plugged in, I can’t really verify if the relay works.

 

[densobro]

Just found a way to test the relay and it does work, I can hear it clicking.

 

[97Kharon]

I’m going to my garage shortly, i’ll see if I have a the same connector off the top of my head I don’t recall seeing a connector. In my previous reply I attached a troubleshoot guide.

There should be a wiring harness right below the cruise control it has red wires that coming out and into the fuse box then there’s two green wires that feed out. There should be a connector there.