I'm trying to get my horn to work to pass inspection.

Checked the fuse...good.

Removed the horn and connected to battery and horn works.

Used voltmeter to test horn terminals and got no response from the voltmeter.

There are two terminals on each of my two horns, one blue wire and one yellow wire. Can anyone tell me which is positive and which is negative?

If the voltmeter is showing no power at the horn terminals when the key is in the on position and the horn button is depressed I am assuming no power is getting to the terminals.

Also, I read on another thread that depressing the horn button grounds the horn causing the honk. If this is the case, can I connect the positive horn terminal directly to the battery and have a working horn?

Also, when searching about horn troubleshooting there is alot of talk about relays. I know how to access the relays but there's 9 of them and I can't find out which relay to check?

Any help I love you.

 

The horn relay is in the back row on the relay component thing, 2nd from the right. Left to right, it goes a big round one, a square one, the horn one (square), and then another one

 

Thanks melon. I'm off to check it out. How did you figure this out?

 

the relay is okay.

i connected the horn directly to the battery and it honked. so im going to have to rig something up to pass inspection. or take apart the steering wheel.

any thoughts?

 

Try the ground connections in the steering wheel. My 1994 940 had minor corrosion on them. I took out the air bag and jiggled all the ground wires. Also replaced the steering wheel switches.

 

Haha. I'm doing that now. As a last resort. Hopefully I don't get a broken nose from accident air bag to the face! I will let you know.

 

Alldata works wonders

 

I got the airbag out. Broke one of the torx screws because i was screwing the wrong direction...doh. anyway i can get one from the junk yard.

how do you remove/replace the wheel switches?

 

I got the switches off, snapped off. nothing too corroded in the switches or behind the airbag, but i cleaned them all anyway. Still no horn.

I am still wondering what the two wires connected to each horn are. One is blue and one is yellow.

I got the horn to honk with the blue wire connected to the horn and the yellow wire unplugged, and i used jumper cables to connect the yellow wire horn terminal to the negative post on the battery. I'm assuming this means the blue wire brings power to the horn and the yellow wire is the ground wire.

If the horn has power and honks when i ground it to the battery then where else could the problem be than behind the airbag?

Behind the airbag there were wires coming from each horn switch, leading to the steering column. one was fixed to the column (ground?) and the other went into a black circle shaped connector in the steering column and it had a spring action...if i pulled the wire out a bit and let go, it snapped back down. Anybody know what that is?

 

The one with the spring is a rotary joint. Try cleaning that. Look closely at the switches as they can get pitted. Try jiggling the fixed one. Mine was some sort of square contact that could be moved slightly. Also look at horn connectors for corrosion at the wire/connector. good luck

 

Well we got the horn working.

I used jumpers to ground the horns to troubleshoot. Starting at the horn and working to the steering wheel. Taking off the top vinyl panel of the steering wheel assembly was the breakthrough. From there I was able to leave the battery connected and confirm that the problem was indeed behind the airbag.

3PO was right it was the ground connection behind the airbag (which i cleaned thoroughly 2 days ago and had given up on. I removed the ground and bent it a little and cleaned it more and now the horn works.

I had to reconnect the battery while the airbag was off to test the ground connection and now my SRS light is on. So it looks like I have another project.

Thanks to all of you who helped me figure this one out.