Horn Grounding Issue

[lsfourwheeler]

So...I'm having a strange issue with my horn wiring in the steering wheel. For some reason, the steering wheel itself is not grounded so when I push the center section in to activate the horn, nothing happens.

I confirmed the horn works if I simply ground the horn wire to the chassis manually.

The way the setup appears to work is the main part of the steering wheel itself is supposed to be grounded, and there are two contacts behind the center airbag portion that contact when you press it in. I checked with a multimeter and the contacts all appear to be working correctly. My issue however is that the wheel itself is not grounded so closing the contacts still doesn't activate the horn.

Not sure why this is? The steering column shows that is grounded to the frame (makes sense as it's bolted to it). Somehow though the steering wheel that is bolted to it is not. Anyone have advice on this?

[Ajzride]

I believe there should be a wire to ground one side of the horn to the column shaft. The other side should feed the relay, when you press the horn the two sides connect and the relay gets grounded.

[Hojo]

2 months ago I kind of posted about this. I’m using a removable steering wheel and don’t have a clock spring. I discovered that the steering shaft that runs through the firewall inside an outer cylinder is held in place by plastic bushings. Therefore, it isn’t grounded. To make the horn work, I had 2 choices. One conventional and harder, the other, easy but admitting defeat.
Method 1
Cut a square hole through the outer steering shaft. Buy a set of brushes for a motor of appropriate size. Attach the end of one brush to a plate and attach the plate to the outer cylinder. The spring inside the brush holds the carbon against the inner steering shaft. Now the steering wheel is grounded. I had to do a similar setup so the other brush rubbed against the giant washer that is the back of the steering hub. After several tries at perfecting this, I bought a momentary on switch that says “ horn” on it and lights up when the ignition is on and placed it on the dash.

[aquillen]

There are several posts scattered in the builds where guys made various slider contacts to get chassis ground into the steering column. Carbon brush is the elegant way, but probably just a metal on metal slide contact of any sort you can cook up will work. Open up a relay and use the contact button/arm if you want something "slick". A little grease will not hurt, especially if silicone super grease, etc. In the end you need ground into one side of the horn button and then out of the button's contact over to the horn relay in the fuse box.

[lsfourwheeler]

Thanks for the info!

So how is the wheel normally grounded in the Subaru? My donor car had a messed up clock spring setup but I bought a new clock spring to replace it. My iWire harness doesn't have any sort of ground that is run to the clock spring connector. The only wire going to the steering wheel is the single horn relay wire.

A momentary button installed in the center console is my backup option. I plan to eventually replace the Subaru steering wheel but that's a while down the road when I feel like spending money on small things.

[Kiwi Dave]

Hi Lawson

If you are using the clockspring, you should be good. I grounded my horn button through one of the clockspring wires to the frame (it doesn't matter which one, as long as it's not the one you are using for the iWire horn wire to the relay). iWire did not provide this ground wire.

Cheers

Dave

[Ajzride]

If you have a clock spring use one of the cruise or ABS wires to send a ground up the column.

[lsfourwheeler]

Thanks, weird iWire hadn't already taken care of that but that's easy enough to do. Only issue is I don't have the pins for the connectors but I can probably just wire in the ground wire directly.

[aquillen]

Looking at an 04 wiring diagram the only place I find a drawing of the steering roll connector is in the airbag section, shows a 2 pin roll connector. Some of the other years that roll connector has 6 or maybe even 8 circuits. They don't really show the horn on a roll connector in this 04 drawing. But that does show you a couple pins you can use (airbag ckt).

[lance corsi]

I used a brush assembly from a 1964 falcon. I put it on top of the column, next to the welded on bracket. If you disassemble the column, it’s easy to see the smooth area for the brush to ride on.

[Kiwi Dave]

Thanks, weird iWire hadn't already taken care of that but that's easy enough to do. Only issue is I don't have the pins for the connectors but I can probably just wire in the ground wire directly.

Just cut off the connector and wire it in by your preferred method after stripping the wire.