VW Horn Ultimate Troubleshooting Guide
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VW Horn / Audi Horn Troubleshooting Guide
Symptom: Horn will not sound (note that the alarm horn is a seperate horn and may still sound even though the main horn will not).
Common Causes
-Bad horn/horns
-Blown Fuse
-Broken Steering Wheel Clockspring
Uncommon
-Bad horn relay - available here
-Bad ignition switch
-Bad connection at horn
Horns not working correctly?
If they sound weak or they have no sound it's time to replace them.
This guide will help you quickly figure out what is wrong, and show you how to fix it.
Option A
You can quickly check your horn by running a positive and negative jumper wire from your battery to your horn to see if it will work when given direct power. If it works then follow the
You can quickly check your horn by running a positive and negative jumper wire from your battery to your horn to see if it will work when given direct power. If it works then follow the
troubleshooting guide below. If your horn does not work with direct power to it them you will need to replace your horn.
(90% of the time, this is the problem)
Option B
Step 1
-If you have a multimeter, disconnect the plugs on the horns and have a friend push on the steering wheel as if they were trying to activate the horn (note: ignition switch must be on). If you have 12V at the horn connector then discontinue diagnosis, your horns are bad.
If you are not getting any voltage then your horn relay has gone bad. Replace horn relay and re-check horns.
Step 2
-Check Fuse #40
Fuse diagram here
-If the fuse is good continue to Step 3.
-If the fuse is bad, replace and recheck the horn.
Step 3
-Turn the key to the on position, but do not start the car.
-Check windshield wipers. If windshield wipers are not working your ignition switch is probably bad. Replace if necesarry.
-If wipers are working go to Step 4
Step 4
(This assumes you have good hearing)
(This assumes you have good hearing)
With the key still in the on position, try to activate the horn. Do you hear a faint electrical clicking sound, (horn relay), when you push on the steering wheel?
If you hear a clicking sound go to Step 4a.
If you do not hear a clicking sound go to Step 4b.
Step 4a
If you do hear that clicking sound, it means that your clockspring is working correctly, and your horn relay is PROBABLY working correctly, but new relays are available here.
Step 4b.
If you don't hear any electical clicking sound then your clock spring is bad, or it has a loose connection.
(Accessing, removing or replacing the clockspring)
-"Joester" a member at TDIclub.com wrote a great how-to for doing this, though it may look complicated it is fairly easy to do.
Click here for the writeup at the TDIClub.com
Don't forget to disconnect the battery cables!
Note: After doing this work, VCDS will probably be needed to reset your airbag light on the cluster
Other notes:
Written by TDIclub member "Alchemist"
"....On Mk4 fuse #40 supplies the horn relay with 12V via relay panel connector S1-4 on a Red/ Brown wire. When the relay operates, the power comes out of the relay panel on a black/Yellow wire at S2-2. This wire goes to the horns on pin 2 of the horn connector. Pin 1 of the horn connector is spliced to a ground wire in the headlight harness."