01 Horn Circuit

my horn sounds really weak. like its only half sounding..oh well

to remove the driver side airbag ( horn contacts is included in the air bag) you have to remove two plugs on the back side of the steering wheel.. under those plugs is a 8mm bolt on each side.

If the horn works with the factory keyless entry remote then you know your problem has to be with the airbag sliding contact ( clockspring) this is a device that rotates with the steering wheel and allows electrical connection to the horn switch, drivers side air bag and cruise control.. or possibly a broken ye/lg wire circuit #6 before splice #249 this splice is located near the gem module.. so the broken wire if it is that would have to be in the column or in the harness under the driver side of the dash.

Most of the time when a air bag sliding contact goes bad you will also have a air bag light on or the cruise control inop, but sometimes only one system will be inop and the others will work.

See http://cgi.ebay.com/ebaymotors/2004...150813018QQcmdZViewItem?hash=item180150813018
for a picture of what a "clockspring" looks like and where it is mounted.

Years ago, the sliding contacts you describe were used for the horn and cruise control switches. These allowed the steering wheel to spin while the cable to the steering column remained fixed. Sliding contacts were too unreliable for air bags, so were replaced with a long flexible PC board that is anchored at both end, and wraps loosely around the steering column several turns within a housing, in the shape of a spiral. When the steering wheel is turned, the outside diameter of the spiral becomes larger or smaller, depending on direction. It resembles the action of the mainspring in a mechanical clock, thus the nickname "clockspring".

PS . . . . Stangnet is the informational website you seek.

I am not aware of any single picture that shows both the circuit and physical location of components as you described. The example you posted pretty much applies to all cars. In the Mustang, the points marked "5V" and "24V" connect together then to the battery (+12V) through a fuse. Other than that, the only difference is the connections to the both ends of the horn switch are routed through the "clockspring" cable. Servicing the clockspring is an involved project, as it is mounted directly behind the steering wheel. Both the driver airbag and steering wheel must be removed to access it. I would want to be 100% sure the clockspring is bad before attempting this repair.

Check your owner's manual. On my '03, pushing the remote "lock" button with the dorrs already locked beeps the horn. If that function does not work, the problem may be elsewhere. Does your cruise control turn on and off, and actually control your speed? It shares "clockspring" wires with the horn circuit. If the cruise control works, the "clockspring" is not the cause of your horn problem. I think the fuse and relay are more likely to fail before the horn switch and "clockspring".

Your aftermarket alarm may not be connected to the horn (no need, since it has a siren). This makes it useless as a diagnostic tool. Do you have a cruise control with on-off and resume-set-cancel switches mounted on the steering wheel?

Does you air bag self-test indicator come on when you first turn on the ignition, then go off after a few seconds?

Both the driver air bag and cruise control share "clockspring" wires with the horn circuit.

Here's the wiring for the car including the horn circuit.

http://rapidshare.com/files/51943828/Wiring.zip.html

ggreenlantern77, just be carefull messing around in there. I don't know who did what to my wheel before I owned the car, but pressing any of the cruise control buttons will set off my horn. The time I learned that was also the time I got pulled over for it.