I am mildly confused

[C101971]

This is my first post here so if this has already been asked and I could not find it, apologies in advance. Anyhow, I know my way around vehicles pretty well, and I ran into an issue driving home from work that I literally have no explanation for after taking apart the whole cab of my c10. It's a 71, and in the middle of driving home my horn decided to short on a piece of metal. No big deal right? Well no it's a big deal, if you can imagine driving in rush hour and your horn goes off whenever you push in the clutch is a big deal. After painfully making it home I pulled up and put the e brake on and turned the truck off. Now the horn won't shut off at all. Disconnected the battery to not draw any more attention then I already had. And checked ALL the wiring, not a nick anywhere, pulled out the relay and put in a universal one I had kicking around that I knew worked. Same problem, horn wouldn't shut off. Wired it to an auxiliary switch, same issue, would not shut off. The only way I got the horn to not make me seem like an idiot was to cut the wire going to the horn or disconnect the battery. Just out of curiosity who has experienced this ridiculous problem?

[Stocker]

Welcome to the board! I'll try to help you, but if not, there are a lot of experts here, and they are eager to offer advice. As designed, the horn circuit is pretty simple. However, a prior owner may have altered yours.

Pressing the horn button sends ground (on a black wire, iirc) to the horn relay on the inside of the firewall, under the dash. The relay then operates and sends 12vdc on a green wire to the horn(s). That's it in a nutshell. If you lift the green wire from the horn, you can troubleshoot the circuit without the horn blowing.

It sounds (no pun intended) like your black wire between the horn button and the relay is getting grounded by the clutch, or something near the clutch. Good luck, hope this helps, and keep us posted!

[dmjlambert]

Welcome. In addition to what Stocker said, a lot can happen since 1971 to the metal and plastic parts underneath that plastic horn button that make the horn work. You may not have a problem with wiring, it may be with other parts. Using a multimeter to figure out the problem may help.

[toolboxchev]

First off just unplug that fricker under the hood, they are really easy to get to.

[C101971]

Originally Posted by Stocker

Welcome to the board! I'll try to help you, but if not, there are a lot of experts here, and they are eager to offer advice. As designed, the horn circuit is pretty simple. However, a prior owner may have altered yours.

Pressing the horn button sends ground (on a black wire, iirc) to the horn relay on the inside of the firewall, under the dash. The relay then operates and sends 12vdc on a green wire to the horn(s). That's it in a nutshell. If you lift the green wire from the horn, you can troubleshoot the circuit without the horn blowing.

It sounds (no pun intended) like your black wire between the horn button and the relay is getting grounded by the clutch, or something near the clutch. Good luck, hope this helps, and keep us posted!

I did check all the wiring, used new wires, switch, and relay and the horn is still going offconstantly, I am going to try buying a new horn to see if maybe the horn itself is causing the problem

[Stocker]

Originally Posted by C101971

I did check all the wiring, used new wires, switch, and relay and the horn is still going offconstantly, I am going to try buying a new horn to see if maybe the horn itself is causing the problem

The horn cannot create its own voltage. Just sayin'

[jessemthompson]

I bet that was an interesting ride home! �� you definitely have a short somewhere.

[stevenfromtexas]

i had bought a new turn signal switch during my build. when i got everything hooked up and was so excited that i was getting closer to being finished, i plugged the green wire to the horn; the horn started blaring and it scared the sh!!!t out of my that i almost split the back of my head on the hood....hahahaha
turns out the hole of the "new" signal switch had a little bit of brass sticking out that was connected to the horn button and grounding on the steering column.

i'm curious if when you push the clutch if its tugging on the turn signal wires and moving the signal switch to do the same thing..... shot in the dark but worth a look

[Stocker]

Just had a thought, is there a chance a PO might have wired an alarm system to operate the horn? Something is sending voltage to the horn. If the horn relay is not being operated, it must be coming from a source other than the relay. Test light or a VOM should help pin this down.