Horn Switch Wiring

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Equilibrium31

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Looking for some input to handle an issue with my horn. My horn quit working a while back and I'm pretty sure it was related to some other work I did in my steering column a while ago. I've tested and verified that it's not an issue anywhere in my power distributor or with the relay. However, I do believe that there is a disconnect somewhere else since pressing the horn doesn't even make a clicking sound at the horn itself. I also don't think it's an issue with the clockspring because I don't have any dash lights on for the airbag.

So, I'd like to check the wiring in the steering column, but the only wire I know for sure that goes to the horn is the one near the airbag and I'm open to advice for checking other connections around here since I'm not sure what most of these wires go to:
100884
 
Imapepper said:
Any clicking at relay when horn button is pushed? Possible to check for switching action using ohmmeter directly at switch in steering wheel?
Click to expand...
No clicking. The wire feeding the switch near the airbag has a single connection. I was testing around with my multimeter, but not sure where the other pin would go to test.
 
Hey bud, I appreciate the follow up. I'm a bit late responding since I haven't had much of a chance to get everything opened up again, but I'm still thinking that the problem has to be somewhere between the battery and the horn switch.

I took the multimeter to the wiring of the horn switch and wasn't able to get a reading. Now, the reading I did was from the positive plug to the switch to the metal where the grounding wire was attached, so I *think* I did the reading right, but I am still pretty new to troubleshooting with a multimeter, so user error is a real possibility.
101462


However, I realized something obvious that I missed when looking at all of this before. The wire to the horn switch is green and red, meaning that the wire I was initially looking for in the steering column should have been obvious:

101463


But I'm actually not sure how that little red tab on the plug works. I know it's there to keep the plug from falling out, but I'm not sure if it needs to be pushed down, pushed up, etc. to allow me to unplug it. I figured rather than just keep stabbing away at it with a screwdriver, I should just come here, haha. Anyone have advice for this part?

And @Imapepper I haven't yet checked to see if wiring the horn directly to the battery will get it to work, but it's on my to do list. However, is it possible to do this from an ODB reader too? I thought I had seen that done before, but it was on a different car (not a Jeep).
 
Not sure on the obd-horn test. Can't help on connector issue either. Check for voltage across the horn switch, should read battery voltage. When switch is pushed voltage should drop to zero engaging relay and connecting 12v direct to horn. Sometimes the horn itself needs a whack to loosen diaphram... good luck
 
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Anyone else have any insight on this? In particular, I at least am looking for advice on dealing with the yellow plug in my last post.
 
Let's take a look at the wiring diagram.

#1 - Starting at the clock spring disconnect, you can check from your yellow connector (pin 1, C1) to the control side of the horn relay (C13). Looks like it's a red/yellow wire. You're going to be checking for resistance, and you should typically expect a reading of less than 1 ohm. If you get a good reading then you know the wiring from the relay to the clock spring is good.

#2 - To rule out the horn, you can take a small wire and just jump the switched side of the relay. Put wire across terminals C15 and C14, if the horn works then you know the circuit is good from the battery all the way down to the ground for the horn.

#3 - You can also check for 12 volts at the relay. Change your meter from ohms to VDC, put the red lead on C11 of the relay terminal and the black lead on C13. You should read battery voltage.

Those three steps will test the entire circuit up to the steering column disconnect. If they are all good then your problem is either a bad horn relay, a bad switch, or a problem in the clock spring.


102234


Also, I don't think you're on the right connector. Looks like that yellow connector you're messing with is for your airbag. C1 is your ticket according to the manual.


102235
 
Last edited:
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Ok, posting since I finally got this fixed. My father-in-law was in town and gave me a hand since he's more experienced with using a multimeter. From checking everything, we finally found that there was an issue with the ground wiring not passing through the clockspring. Ideally, I would have replaced the clockspring, but since I still have extra wiring for cruise control in my steering wheel (even though I don't have cruise control in my SE), we were able to cut back the cover on one of those wires, which had a good ground wiring connection, and use some spare wire to connect the ground from there to the ground wire for the horn switch. It saved me around $100 since I didn't have to replace the clockspring and my horn is working once again.

Thanks for all the help and resources here that helped us to narrow down the cause.
 
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qslim said:
Let's take a look at the wiring diagram.

#1 - Starting at the clock spring disconnect, you can check from your yellow connector (pin 1, C1) to the control side of the horn relay (C13). Looks like it's a red/yellow wire. You're going to be checking for resistance, and you should typically expect a reading of less than 1 ohm. If you get a good reading then you know the wiring from the relay to the clock spring is good.

#2 - To rule out the horn, you can take a small wire and just jump the switched side of the relay. Put wire across terminals C15 and C14, if the horn works then you know the circuit is good from the battery all the way down to the ground for the horn.

#3 - You can also check for 12 volts at the relay. Change your meter from ohms to VDC, put the red lead on C11 of the relay terminal and the black lead on C13. You should read battery voltage.

Those three steps will test the entire circuit up to the steering column disconnect. If they are all good then your problem is either a bad horn relay, a bad switch, or a problem in the clock spring.


View attachment 102234

Also, I don't think you're on the right connector. Looks like that yellow connector you're messing with is for your airbag. C1 is your ticket according to the manual.


View attachment 102235
Click to expand...
This is a good example of why I love this forum. Some of the nicest most helpful people around.
 
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Just wanted to revive this thread because it already has so much info.

I am having a similar issue with my horn not working. The relay is not clicking, so I know its on the horn switch to relay side (I also jumped the relay at C14&C15 and the horn sounded).

I disconnected the wiring at clock spring as @qslim advised and took a resistance reading with ohmmeter and it was less than 1. I have voltage at the red wire connected to the switch, and the ground connects to a stud on the airbag, which I think grounds through yellow connector on airbag itself.

So my issue must be in the switch, right? I took the switch out and took an ohm reading, nothing (but I'm not sure its supposed to?) The switch has no function to it, it doesn't feel like i'm pressing anything.
OCUMbV+PSUqYCXBwnTfPcQ.jpg

Is this something you can replace? I can't find a part online for it...
Thanks
 
Axeman said:
Just wanted to revive this thread because it already has so much info.

I am having a similar issue with my horn not working. The relay is not clicking, so I know its on the horn switch to relay side (I also jumped the relay at C14&C15 and the horn sounded).

I disconnected the wiring at clock spring as @qslim advised and took a resistance reading with ohmmeter and it was less than 1. I have voltage at the red wire connected to the switch, and the ground connects to a stud on the airbag, which I think grounds through yellow connector on airbag itself.

So my issue must be in the switch, right? I took the switch out and took an ohm reading, nothing (but I'm not sure its supposed to?) The switch has no function to it, it doesn't feel like i'm pressing anything.View attachment 187106
Is this something you can replace? I can't find a part online for it...
Thanks
Click to expand...
Sounds like you about narrowed it down, the only things I can think of that you didn't check based on your description is the ground side & the relay itself. I know you said the relay isn't clicking & the horn sounds when you jump the terminals in the PDC, but did you try swapping the relay out?

You could also check the ground side by touching one lead to the steering column jacket & a known good ground or the negative battery cable. You should be getting good continuity there.

The manual actually has a pretty good diagnosis section for your '06 starting around page 8H-2, it also states that you should have no continuity through your horn switch:

1) Disconnect and isolate the battery negative
cable. Remove the steering column opening cover
from the instrument panel.

(2) Check for continuity between the metal steering
column jacket and a good ground. There should
be continuity. If OK, go to Step 3. If not OK, refer to
Steering, Column for proper installation of the steering
column.

(3) Remove the driver side airbag module from the
steering wheel. Disconnect the horn switch wire harness
connectors from the driver side airbag module.

(4) Remove the horn relay from the Power Distribution
Center (PDC). Check for continuity between
the steering column half of the horn switch feed wire
harness connector and a good ground. There should
be no continuity. If OK, go to Step 5. If not OK,
repair the shorted horn relay control circuit to the
horn relay in the PDC as required.

(5) Check for continuity between the steering column
half of the horn switch feed wire harness connector
and the horn relay control circuit cavity for
the horn relay in the PDC. There should be continuity.
If OK, go to Step 6. If not OK, repair the open
horn relay control circuit to the horn relay in the
PDC as required.

(6) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no continuity.
If OK, go to Step 7. If not OK, replace the
faulty horn switch.

(7) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch.
 
qslim said:
(6) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no continuity.
If OK, go to Step 7. If not OK, replace the
faulty horn switch.

(7) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch.
Click to expand...

So this is where I am stuck at, I don't have any continuity in the copper switch pad. It doesn't really have a pressing motion where it recoils because its just a pad? I don't get continuity when pushing the pad against the flat plastic tray though.

I did try swapping out a known-good relay with the horn relay and got nothing.

I saw on another post where someone grabbed a better ground wire out of the steering wheel where it is prewired for cruise control buttons. I don't have CC, but there is wiring to where the button would be.
 
Axeman said:
So this is where I am stuck at, I don't have any continuity in the copper switch pad. It doesn't really have a pressing motion where it recoils because its just a pad? I don't get continuity when pushing the pad against the flat plastic tray though.
Click to expand...

Gotcha, that membrane thing is supposed to complete the circuit when you squish it between that plastic tray & the steering wheel pad, so you should read no continuity when it is static and continuity when you press the pad.

When the center area of the driver side airbag trim
cover is depressed, the electrically conductive grids
on the facing surfaces of the horn switch membranes
contact each other, closing the switch circuit. The
completed horn switch circuit provides a ground for
the control coil side of the horn relay, which activates
the relay. When the horn switch is released, the
resistive tension of the convex membrane separates
the two electrically conductive grids and opens the
switch circuit.

One last thing I would check is the ground where that black pigtail connects on the steering wheel frame, if you have good continuity there to ground then I'd say that membrane is your problem.
 
qslim said:
black pigtail connects on the steering wheel frame
Click to expand...
The black pigtail on mine grounds to the airbag. The airbag bolts into the frame so it should also be ground. Is there a way to jump the horn wiring at the membrane safely? or at the membrane itself?
 
Axeman said:
The black pigtail on mine grounds to the airbag. The airbag bolts into the frame so it should also be ground. Is there a way to jump the horn wiring at the membrane safely? or at the membrane itself?
Click to expand...
I’m not sure, in order for that switch to work it has to be sandwiched in there. It’s been awhile since I had mine apart so can’t remember if that pigtail is accessible when everything is assembled. You could just check for continuity to ground where the airbag mounts if that is your line of thought.
 
qslim said:
I’m not sure, in order for that switch to work it has to be sandwiched in there. It’s been awhile since I had mine apart so can’t remember if that pigtail is accessible when everything is assembled. You could just check for continuity to ground where the airbag mounts if that is your line of thought.
Click to expand...

Just an update,

I jumped the red signal wire from the switch directly to the steering wheel bolt (known ground) and BEEP! so now I know that the wires running up to the horn switch are good. So at first I thought it was my ground wire, so I lengthened the wire and attached it directly to the steering wheel rather than how it was to the airbag
Z1sTb6oTTIWm4135RYaZhg.jpg

aDOZW9wWQrK3mg+6LhylUQ.jpg

This didn't solve the issue though.

Next I took a few resistance readings with Ohmeter:
GtZ+IRlzSuSceP+pvcQFEg.jpg


I was getting nothing from the switch with pressing it. So I took a good look at it figuring, what the heck could go bad on a copper pad that is safely inside the steering wheel?

Then I found it! the copper lead to the red wire was cracked in half.
4+t1hpF7TH2o0REGUomFUg.jpg

I couldn't get the camera to focus for this close up, but the round eye is no longer connected to the copper strip that runs between the eye and the pad.

So I broke out the ol' soldering kit and made a mess:
nt0Xpp4NSsirJKUwrh7YLA.jpg

It's certainly not pretty, but hell if it don't work! I have a horn again! (this is a vital piece of equipment for us Masshole drivers). I will eventually need to source a used horn switch, I don't believe I can buy a replacement without getting a whole airbag for some reason.

Thanks again for your input, and hopefully this helps someone else.
 
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