Horn

[Eagle]

Hi have a 67 dodge d100 it keeps blowing fuse for the horn when I turn the key to on any help thank you

[Wildergarten]

Hi have a 67 dodge d100 it keeps blowing fuse for the horn when I turn the key to on any help thank you

This problem has the stench of a wiring harness that has been jury-rigged under the dash to bypass a prior failure. All sorts of bad stuff could be happening. MANY of the electrical problems in this truck are caused by an alternator line that overheats and melts insulation inside the harness because Dodge used only 12AWG wire for that circuit. That harness is where I'd look first.

The horn circuit, being a large wire with 30A that is seldom used is a definite candidate to be tapped for other uses. That unswitched line is supposed to go from the fuse block through the firewall to the horn. The ground leg from the horn is switched by a relay that itself sends a ground leg for the relay coil back through the firewall to the switch on the wheel. The horn itself is only supposed to work when the coil side of the relay is grounded at the switch.

The horn is only SUPPOSED to get power from the fuse on the unswitched side of the circuitry (it's supposed to work with no key). If someone tapped that line, you likely have a short from the unswitched horn circuit line going to ignition switch as a source of power for those switched circuits as an alternative to something that had previously failed. This suggests a second problem of a shorted line somewhere downstream from the ignition switch.

Sorry I can't be more encouraging, but this sounds like an all-too-common mess.

[Hobcobble]

I would suggest disconnecting your steering column harness and fishing
the wires out of the column. There might be a bare portion of the wire
that's contacting the column or steering shaft.

John

[Eagle]

Thanks for the help

[PwrWgnDrvr]

I would suggest disconnecting your steering column harness and fishing
the wires out of the column. There might be a bare portion of the wire
that's contacting the column or steering shaft.

John

If its the horn wire in the column that's bare and touching ground, the horn will just sound continuously, it won't blow a fuse.