Fuse / horn question

[1978sierra]

Hello all,

I recently had to replace my ignition lock cylinder, I got everything put back together and functioning properly. The horn blew loud. I then noticed I put my wheel back on a few degrees off so I pulled it off to realign it. While it was off I depressed the horn contact pin by accident with a screwdriver and the horn honked and a spark happened at the contact pin. I then replaced the wheel.

Now my horn won't honk. Figuring I'd blown a fuse I got down to take a look but I'm not sure which fuse to replace / they look ok.

Here's a pic for reference. Any help would be greatly appreciated.

You guys rock

[CSHADES]

The way the horn works is when you push on the horn button it grounds the control side of the relay for the horn. I can't remember with out looking at mine if the relay is in the fuse panel or under the hood but it should make a click noise from the relay when you push the horn button that you should be able to hear. If it doesn't that would make me think you have something going on where you were working in the column. The horn contact parts are a little on the fragile side and easy to break. Did you get everything to the horn button hooked up? If you want to check the fuses just turn the key on and use a test light on each end of each fuse if one end doesn't light the test light you have a bad fuse.

[1978sierra]

Originally Posted by CSHADES

The way the horn works is when you push on the horn button it grounds the control side of the relay for the horn. I can't remember with out looking at mine if the relay is in the fuse panel or under the hood but it should make a click noise from the relay when you push the horn button that you should be able to hear. If it doesn't that would make me think you have something going on where you were working in the column. The horn contact parts are a little on the fragile side and easy to break. Did you get everything to the horn button hooked up? If you want to check the fuses just turn the key on and use a test light on each end of each fuse if one end doesn't light the test light you have a bad fuse.

No click when I press the horn down. Like I said everything was working properly until the spark. Now nothing. I'm certain that it's all hooked up correctly in the column. Where do I look under the hood?

[CSHADES]

I still think you have a problem in the steering wheel side. Do you have a test light? If you do hook the test light ground end to power(12 volts) and probe the black wire in the turn signal switch connector and push down the horn button if it lights then you are good on the steering wheel end. If it doesn't light then you have a issue at the top of the column. The spark you had doesn't mean much because you are at the ground end of the horn system control. You could ground the horn contact all day long and not blow the fuse.

[cadillac_al]

The relay is usually taped to something near the fuse box. It's a square thing and should be within 6-10" of the fuse box.

[400/400]

Could be the pic, but it looks the the 20A fuse to the left of the upper red wire is blown.

[1978sierra]

Originally Posted by 400/400

Could be the pic, but it looks the the 20A fuse to the left of the upper red wire is blown.

You were right, that fuse was blown, I replaced it and.... nothing, I wonder what it controls?

Anyway, Here's the update- no click or anything when I depress the horn, just pulled the wheel and took some pics for you guys to review.

I know noting about electrical, just went out and bought a multimenter, but I don't know what I am doing with it, so any specific instructions to help me diagnose my lack of horn would be amazing.

I also think I found the horn relay, is this it in the pic?

[CSHADES]

I assume you took it farther apart then that when you changed the lock cylinder correct?
The way to test what you have right now with a multi meter is---- at the bottom of the steering column is a connector for the turn switch disconnect it and hook one of the wires from your meter to the black wire on the column side connector and hook the other wire from the meter to the button sticking out of the plastic piece at the top of the column in your pic. Set the meter on ohms and see if it has continuity. I also noticed in the pics that there is a wire nut in your harness that needs to be removed and replaced. No that is not the horn relay---if I have time I will go and look at mine and see where the relay is.

[1978sierra]

Originally Posted by CSHADES

I assume you took it farther apart then that when you changed the lock cylinder correct?
The way to test what you have right now with a multi meter is---- at the bottom of the steering column is a connector for the turn switch disconnect it and hook one of the wires from your meter to the black wire on the column side connector and hook the other wire from the meter to the button sticking out of the plastic piece at the top of the column in your pic. Set the meter on ohms and see if it has continuity. I also noticed in the pics that there is a wire nut in your harness that needs to be removed and replaced. No that is not the horn relay---if I have time I will go and look at mine and see where the relay is.

Yes, I pulled it down past that to change the cylinder, had to bang out the flashing to get at it. When I put it all back together the horn worked correctly, it wasn't until I took the wheel off and depressed the button (causing a spark) that it stopped working. I'm hoping that I didn't somehow fry the next contact spring in the turn-signal cam as taking off that lock ring is a pain.

Thanks for the advice with the multimeter, I will give that a shot tonight!

Thanks !!