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I have search the forum to try and figure out why the horn isn't working.
I confirmed that the relay is good.
Can't confirm if the horns are good. I put power to them but nothing. I could be testing it wrong... 🤷
Just a little background. The air bag is no bueno.... So it's there for decoration for now..
Could it be since the power runs through the air bag module and air bag is isn't working, that it's not getting to the buttons?
A bit lost and trying to understand how to wire just the horns to work.
Am not sure if you have 93 or 94 and if 93s are least wired the same.
I'd check the fuse first.
You can trace the connectors and lines to see where it's short.
Airbag module described in WSM refers to passenger airbag connector over the glove box, not the module underneath the dash.
Horn and airbag connector lines do run together toward passenger firewall, confirmed in 94 model
It is a 93. The horn does look a bit oxided. Maybe that's it? Is there a way to test the horns itself? Meaning putting power to them or they work off of ground.
I'll look over that link..
On 1994 models, there were 2 air bags. The steering wheel horn buttons operate the relay by grounding it. The buttons connect to the horn relay through the passenger side air bag module. If that module is missing or either of its 2 connectors are disconnected, the horn relay won't operate when you press the buttons, so neither will the horns.
On 1993s, there was a steering wheel air bag only. The horn buttons ground the horn relay directly, and the relay then sends positive voltage to the horns.
To test the horns, apply battery positive voltage to the horn's terminal.
Last edited by Retserof; Jul 14, 2022 at 10:45 PM.
On 1994 models, there were 2 air bags. The steering wheel horn buttons operate the relay by grounding it. The buttons connect to the horn relay through the passenger side air bag module. If that module is missing or either of its 2 connectors are disconnected, the horn relay won't operate when you press the buttons, so neither will the horns.
On 1993s, there was a steering wheel air bag only. The horn buttons ground the horn relay directly, and the relay then sends positive voltage to the horns.
To test the horns, apply battery positive voltage to the horn's terminal.
The hazards are working hence the fuse is not blown. The car is a 93. I'll try putting power to the horns terminal tomorrow.
Horn itself grounds to the front frame, it takes single positive wire.
You can test them with 12v jumper etc, but you'd have to take the front bumper off.
Or perhaps you can reach the LH side horn that is mounted by the oil cooler.
Scratch all of the above! I just discovered that the harness was cut off completely 🤦. It's the harness for the clock spring which feedsthe air bag and horn. I don't know who or when it was done. 😤
I know this kind of gets away from the original issue but....
I took off the steering wheel and discovered a plug disconnected. Anyone know what this is? (see picture)
Also the clock spring doesn't have tension. Is it supposed to be like that?
It does have instructions to set it but when I do the plug sticking out doesn't end up being where it should be which is at the bottom centered.
I'm trying to start from the horn buttons themselves but at a lost on how to test them to see if internally they make a connection.
Now if the buttons are not the ones sending power to the horns then the power travels to the buttons??
If so then I should be reading power at the blue plug that the horn buttons and air bag plug into right??
I'm to old for this diagnostic rabbit hole... Lol
Any way to bypass all this? I just need a horn to pass inspection 😁
Last edited by coolrotariesR1; Jul 16, 2022 at 09:50 AM.
So I found the where the wires are cut but I don't seem to find the other end of those wires. The only other with pertaining to the horn is the green/red wire coming from the steering wheel. Anyone have a good Pic to share of this?
The air bag situation definitely adds a layer of complexity. It's possible that the lack of function there could be affecting the horn circuit, but I'm not entirely sure. Have you tried bypassing the air bag module altogether to see if that makes a difference?
Air bags and horn are also tied to the alarm system which runs through CPU2. Anything blue loom is Air Bag Harness, and sadly the bit I left out of my wiring connector guide. However, from the horns I have this (based off a 94 so your 93 may differ, I believe in the 94s its solid P with no stripe):
Power running to the horns themselves is G/R - coming through the Front Harness
The wire that comes from the Joint Box in the airbag harness is P/B (2 of them!)
The wire coming from the horn switch in the steering wheel is P/B - like Retserof said, it just activates a relay
G/O wire comes from the airbag harness sensors to the horn switches - to sound the horn in an accident
The first pic you have circled is for the illumination bulb to the ignition switch/key (your wires are G/W and L/R, in a 94 its L/R and GY/R)
If all else fails you can wire a separate switch for yourself to pass inspection, nothing says the horn has to be on the steering wheel, just accessible.
The air bag situation definitely adds a layer of complexity. It's possible that the lack of function there could be affecting the horn circuit, but I'm not entirely sure. Have you tried bypassing the air bag module altogether to see if that makes a difference?
As for testing the horns, sometimes it's tricky to get the right setup. Maybe try testing them with a different power source just to rule out any issues there.
And hey, if all else fails, maybe it's time to consider some aftermarket horn options. I stumbled upon https://bosshorn.com recently, and they seem to have some interesting solutions that might work for you.
