My horn is broke and I need to fix it. Where are the relays and fuses for the horn on a 2003 4.0?


I broke the clockspring. The next week the horn blew for a solid 20 minutes until it just stopped. I replaced the clockspring. That fixed the airbag and cruise but not the horn.

The book says


I do not have a fuse in #35. But I hear clicking from this thing behind the passenger airbag when I press the horn. Remote keyless anti theft box.

 

Yes, if you have a factory security system(CSM = Central security module) then the security module needs to use the horn as a warning device so it was wired differently, so no Fuse #35 in cab fuse box, the clicking in that module means the horn buttons and clockspring are OK but most likely horn power fuse is blown.

2003 wiring diagram shows 3 fuses powering the security module but doesn't designate which one is for the horn.
In engine fuse box check #33(15A) and #8(20A)
In cab fuse box check #11(7.5A)

 

Thank you, Ron!

All of those fuses look good as best as I can tell. I'll try replacing them to be sure before getting a new horn. That's the only other thing I think it could be.

 

I would get a test light or volt meter, hook it up to the horn wire and test if horn is getting power that way.
Horns just don't need to be replaced that often, but yes being active for 20 minutes straight could have caused it to fail.

Could get an A Ooga horn, lol, or Dukes of Hazard horns

 

So the horn doesn't blow now correct?

Disconnect the horn and apply 12 volt power straight to the horn and see if it blows. Horn needs to stay bolted down to give it a good ground.

Horns most likely have a duty cycle (just like compressors and welders). They are only meant for short bursts. The long time that it was being blown most likely heated up the inductor coil inside and it broke connection.

 

Thanks, I will try that.

I actually have been contemplating getting a dixie horn just for laughs.

It does not. I'll try that too. Thanks.

 

Tested it out and horn is getting power but no sound. So new horn it is.

Any good replacement options that are plug and play?

 

I put the two note horns from an f250 on mine. Same connector. Just had to rotate the horns some since there are two instead of one.

 

i vote dixie but thats just me

 

x100

 

I was wondering who that was that was giving me the "Finger" the other day...! :)