DIY Horn Switch Replacement

Mauricio Pelissari · October 27, 2015

Well, first a little story why all this, well, i had to remove Fuses 22 and 23 from the fuse box since my horn was sounding continues with me pressing it, and from the manufacture service manual stated as below:

HORN SYSTEM TEST TABLE

WARNING: Disable the airbag system before attempting any steering wheel, steering column, seat belt tensioner, side airbag or instrument panel component diagnosis or service. Disconnect and isolate the negative battery (ground)

cable. Wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to follow these instructions may result in accidental airbag deployment and possible serious or fatal injury.

CONDITION POSSIBLE CAUSE CORRECTION

HORN SOUNDS 1. Horn control circuit shorted to ground. 1. Find the short and repair as necessary.

CONTINUOUSLY.

NOTE: IMMEDIATELY 2. Pinched horn switch wire under driver airbag module. 2. Replace the horn switch.

UNPLUG HORN

3. Inoperative horn switch 3. Replace the horn switch.

HORN SOUND INTERMITTENTLY AS

THE STEERING WHEEL IS TURNED.

1. Pinched horn switch wire under driver airbag. 1. Replace the horn switch.

2. Inoperative horn switch. 2. Replace the horn switch.

So most of the troubleshooting was to replace the horn switch, as I was hopping that my was not a short issue other wise i would have to look very deep, and these are a nightmare to find.

So after continuing with the service manual:

SWITCH, HORN REMOVAL

REMOVAL

WARNING: On vehicles equipped with an airbag, refer to Restraint SERVICE INFORMATION article for warnings and cautions before servicing the horn switch.

Followed the below steps as it was mentioned on the manual it self:

1. Disconnect and isolate the battery negative cable. (On the Air bag Manual says to wait a full 2 minutes for total power drain, but just to be 100% sure i waited 30 minutes and even disconnected the battery it self both negative and positive poles, just in case)

2. Remove the driver airbag. Refer to Restraints/AIR BAG, Driver - Removal . (On this part on the service manual that i got well no AIR BAG and Restraints Parts, so i went to the web and found a very good Grant wheel replacement that mentions the air bag and some others web site showing what to do, but nothing in bigger details, so in the end i found that there are two 10 mm bolts on the wheel holding the air bag it self, so i removed both of them, and with the finger pushed the air bag unit from inside out, instead of pulling from the front of the wheel, i found more easily. after this removal i could see the 2 wires connected to the air bag unit and removed them easily again, Please note that when handling the air bag always point away from your body at all times just to be 100% sure, after removal and just placed the air bag in the bench facing it up as i found instruction on the web. Once i got the air bag out of the way it was easy enough to work on the horn switch so i continued with the following on the service manual.)

4. Remove the three mounting fasteners. (Well for this part you will need a Torx set, after removing the 3 bolts carefully remove the horn switch from the plug it self.)

Once i had the horn switch out, just measured the two contacts between them with a multi-meter in ohms scale to to be sure that it was not shorted between them and to ground. (luck on my side, it was good)

When i got to this point i had installed the new horn switch, and just before i connected back into the plug i used again the multi-meter in ohms scale and on the 2 contacts that you guys will be able to see on the photos in attachment and tested all four horn switch points, and all worked ok, after connected back to the plug it self, and started the reverse process to install the air bag unit on the wheel it self, placed the air bag connectors as per the color code on the back, placed on the wheel, then placed the two 10 mm bolts back and that part was done, pushed the horn on all four points to see the proper movement and then connected the battery back, place back the fuses on the fuse box on fuse 22 and 23 as per drawing and tested the horn & horn was working once again... :-)