Hyundai Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
I've recently bought a 2007 Tucson GLS. A few weeks back i noticed that the horn was not working, but somehow it still passed safety inspection. So far i have taken the Horn itself out of the car, tested it and it worked. I have taken the airbag out of the steering wheel, connected power directly to the switch that activates the horn, and still nothing. I re-grounded the horn to see if that was the problem and still nothing. Checked all fuses and relays and everything looks good. I thought it may be the clock spring but i have cruise control that is working fine so it's probably not that? If anyone could point me in the right direction on where to look next that would be great. Thanks
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
16,095 Posts
There are two circuits involved in making the horn work. The first step to diagnosing the issue is to figure out which of the circuits is causing the problem.

My suggestion is to remove the horn relay from the engine bay fusebox and perform a relay bypass test to see if that makes the horn sound. If the horn sounds you know the relay load circuit is OK (horn, it's ground and the wiring between the horn and the fusebox) and the fault is likely to be on the relay control circuit (horn switch, it's ground, clockspring and the wiring between the clockspring and the fusebox).

To perform the bypass test, remove the horn relay then use a short link wire to bridge the two terminals of the relay socket on the fusebox as shown in the diagram below.

Let us know if the horn sounds or not and we can decide what to test next.

Regards.
Scottie.

 

Attachments

·
Registered
Joined
·
17,552 Posts
Simple circuit.. I show (2) horn on USA model,, each horn sports it' own 2 wire connector.. Black is ground,, Pink is positive sent down line to sound horn with actuation by driver in cabin..

15A horn fuse provide source voltage to relay coil and horns

Ground to fire relay comes from horn pad,, through clockspring cable to coil relay

Start with DVOM at horn connector, verify ground and signal,, seeing you have horns out

Move inside, short the wire to ground at steering wheel.. no sound of horn ---

Remove small white connector off bottom of clockspring,, short pin 6 (red wire) to ground,,, if horn sound,, you have open circuit in clockspring
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4
Thanks for the help so far! I used the jumper wire and it made the horn sound. So what are the next steps from here?
 

·
Registered
2007 Honda CRV
Joined
·
4,601 Posts
Next step should be to look at the control side of the horn relay
Electrical schematic would help a lot here
But would say you have an open or shorted wire to the horn relay

Note the color of wires going to the horn relay (if possible)
 

·
Registered
Joined
·
17,552 Posts
Thanks for the help so far! I used the jumper wire and it made the horn sound. So what are the next steps from here?
Read last 2 portion of post 3 slowly
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
16,095 Posts
I used the jumper wire and it made the horn sound. So what are the next steps from here?
If it was me I'd do the next simplest thing and try swapping the horn relay with one of the others on the fusebox to see if that gets it working. Any of the other blue relays in the photo I attached earlier would do.

The other thing I'd do before removing the airbag again is use your voltmeter to check that there is voltage being supplied to the relay coil.

Connect the black meter probe to battery negative,
remove the horn relay,
touch the red meter probe to each of the 4 terminals on the relay socket in the fusebox.
Make sure 2 of the terminals have 12V.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #8
Sorry for the slow updates. But i have taken the steering wheel off and grounded the red wire pin, and the horn did not sound. I then tested the relay socket and found that only one pin has power (the very top pin, closest to the firewall.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
16,095 Posts
i have taken the steering wheel off and grounded the red wire pin, and the horn did not sound. I then tested the relay socket and found that only one pin has power
You did the tests the wrong way round but at least you've identified the fault.
There is an open circuit in the wiring inside the fusebox. It's quite common to get corrosion inside the Tucson fuseboxes, causing high resistance or even wires to completely break. There are already a few threads on the Tucson forum about it.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #10
Haha yeah i wasn't really thinking when i did the tests in that order, but oh well. If there is an open circuit in the fuse box, is it a very hard job dissembling it and splicing in a new wire?
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
16,095 Posts
I've never had to do the job personally but I'm sure it will be a PITA. But on the bright side, at least it is repairable unlike a lot of more modern fuseboxes.

You'll need to disconnect the battery, then unbolt the fusebox and remove the bottom cover to expose the wiring inside. Find the bottom of the horn rely and check for any signs of corrosion or wires that have come adrift.
 
1 - 11 of 11 Posts
Top