86' 6.9l blowing fuses

[mntwins7]

The horn didn't work when I bought the truck, so I looked in the manual to find the horn fuse, and figured out it was blown. I bought some new 20amp fuses and it blew immediately. So I tried it for a second time - same result. Anyone have ideas? Thanks!

 

[USNENFTS]

My guess would be that there is a short/ground in that circuit somewhere. Probably the horn itself maybe. i would follow the wires and look for anything that is extremely corroded/broken/loose, if nothing is found, then replace the horn.

 

[mntwins7]

My guess would be that there is a short/ground in that circuit somewhere. Probably the horn itself maybe. i would follow the wires and look for anything that is extremely corroded/broken/loose, if nothing is found, then replace the horn.

Alright. I'll take a look at the wiring. Gonna get a pair of horns anyway.

 

[Waystro]

Which fuse is for the Horn?
Mine doesn't work either

 

[mntwins7]

Its a 20 amp on the bottom left

 

[Waystro]

Thanks I'll take a look at it.

 

[chris142]

Does it blow immediately or when you try to honk it?

 

[mntwins7]

Does it blow immediately or when you try to honk it?

Immediately.

 

[mntwins7]

To bump this thread, I realized the fuse goes to the horns and cigarette lighter. However, the previous owner cut the cable on the cigarette lighter, so it isn't connected. Could this be the issue?

 

[madpogue]

If it's the positive wire the PO cut, and that wire is touching metal (ground) somewhere, then yeah, it'll blow the fuse right away.

 

[mntwins7]

If it's the positive wire the PO cut, and that wire is touching metal (ground) somewhere, then yeah, it'll blow the fuse right away.

Alright. I'll check that out.

 

[mntwins7]

Alright, I have to revive this thread with some questions.

So I was looking into why the horns weren't working, but then I remembered the cruise control on the truck doesn't work either.

Another forum post told me that on the models with cruise control, the horns and cruise control shared a relay, otherwise there was no relay for the horns.

Which leads me to the question - has the horn/CC relay gone bad?

If so, where is said relay located?

And would this be the cause of the fuse blowing immediately?

Thanks!

 

[79jasper]

On my 88 it was up behind the dash on the firewall, towards the center. Iirc.

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[mntwins7]

On my 88 it was up behind the dash on the firewall, towards the center. Iirc.

Sent from my SAMSUNG-SM-G890A using Tapatalk

Okay cool. Guess I'll swap that out and see if that fixes it.

 

[79jasper]

It's not a normal relay though.
https://goo.gl/photos/cX582JV2bticVR8z5

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