Horn goes bananas when headlights turned on!
 

my horn goes nuts when i flip the headlight switch.
the parking lights can be on without issue.

i had smoke trickle from the switch once, and from the driver's side headlight as well. upon inspecting, could see nothing. smoke ceased, and horn quit going crazy.

this common? any ideas? how difficult to take apart the switch?

thanks folks!

this vehicle has been super reliable so far!

Horn still going nuts. I disconnected driver side headlight to drive without burning out the horn... Not sure what's next

sounds like something shorted and then burnt up in the process. i would look at the wires to determine what has failed.

What could have failed do u think? The headlights, horn, parking lights, everything works, just so happens to engage the horn when headlights are turned on. Fuse? Relay? Just connections?

I'll dive into it. Soon here

I have this same issue (1994 S10 4X4) and when I turn on the hi beams the horn stops. I think it's the turn signal/hi beams switch. Let you know for sure when I change it

Check your grounds...

My vote goes to the multi function switch. The one wire that activates the horn goes through this switch. A short through this switch could cause it to get power from the headlight circuit. Both the low and high beams do run through the multifunction switch.

If the horn stops when you disconnect the left headlight, my vote goes to a bad ground. Possibly the radiator core support lost ground, (headlights and horn both ground to the support).

This ^
Headlight and horn are both grounded on the same location on the core support.

To get to this ground, You will have to remove the air filter box, and take off the horn, then you will see the core support and the bolt that holds both grounds. Pull them off, clean them both off really well, take some sand paper, and or a wire brush and clean all points off, add some dialect grease, and bolt it all back down.

Do I really need these special tools the manual notes?