[NCangler]

Hi all. First post and thanks in advance for your help.

I have been working on issues with an Excursion that my daughter acquired and when it came time to inspect the vehicle I realized the horn did not work. I took the wheel well off to access the horns and discovered they did not work, so I ordered new horns. I hooked up the new horn and it blows continuously, so I disconnected it. The horn fuse does not blow and I can hear the relay clicking when I press the horn on the steering wheel. I saw some discussions about replacing the horn "bladder" in the steering wheel and other discussions on replacing the clockspring and yet others about the horn relay being bad, which requires replacing the entire fuse block as it is built into the 2004 Excursion fuse block.

I removed the horn bladder and cleaned it but that didn't help, so I'm removing it this morning to try to find a replacement part somewhere. If I can't find a replacement then I'll try the repair outlined in another thread on this site "Sticking Horn Contact Fix" to see if that works.

I could just connect an external horn button to pass inspection but I'd like to fix it the right way if possible and I'm not sure which wires to connect into for an external horn as well. What complicates the situation is it appears under the dash that someone had done some rewiring related to the vehicle alarm system (which I don't know if it works or not). I would attach some photos of the wiring under there, but I obviously need to make more posts first. It seems to be a mess and I don't know what they did or why they did it.

If anyone can advise on the wiring or if you have suggestions on the "bladder" fix or how to wire up an external horn button so I can pass inspection, I would be most grateful! It is already past due.
Randy

 

[NCangler]

Hmmm...it looks like the system allowed me to post the photos after all unless I am the only one seeing them.

 

[Hydro]

So ...if you hear the relay click when you press the horn button, then that part is working -- at least to the relay

From the pictures you posted, I think the security system is causing the horn to blow
or some wires are "together" -- tape job looks sketchy

 

[NCangler]

I agree it looks very sketchy! I guess I need to find a qualified vehicle electrician to sort it out.

 

[Hydro]

I suppose it depends on how "handy" you are with a schematic and electrical test tools

 

[Hydro]

Do you think the alarm system is working partially -- blowing the horn, but not disabling the vehicle?

 

[NCangler]

I suppose it depends on how "handy" you are with a schematic and electrical test tools

Not very! I work better from Youtube videos than schematics but I can figure it out eventually if I have the drawing.

 

[NCangler]

Do you think the alarm system is working partially -- blowing the horn, but not disabling the vehicle?

I don't know. If I plug the horn in it blows continuously so I haven't had a chance to figure out if the alarm system works or not.

 

[NCangler]

I think I'm going to try the fix to the horn bladder today and if that works then I can figure out if the alarm system is functioning or not. If I could lay my hands on a schematic for the 2003-2004 Excursion wiring though that would be very helpful in the correcting of the wiring under the dash.

 

[Hydro]

Connect a light to the horn connection, that way the neighbors will be happier

You mentioned the relay was clicking when you pressed the horn button -- so no need to look farther at the steering wheel

I don't have a specific diagram for the Excursion, but I would think the pickup trucks would be the same as far as the horn circuit

The cruise controls and the horn are on the same circuit -- it works by varying resistance to the PCM on a single wire
do the cruise controls function?

 

[Hydro]

A code reader would help in this situation -- there will codes
Forscan and an OBD adapter

Lite for your phone or tablet or full version for the laptop
Bluetooth for Android or WiFi for iOS
either will work for the laptop, depending on it's capabilities

 

[Hydro]

Here is a diagram of the speed control and horn circuit

 

[Heavy_GD]

google this one, there is a pad under the cover on the steering wheel that goes bad.

For inspection put the horn on a switch.

 

[voodooridr]

The horn switch repair kit is a
6C3Z-13B802-C

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[NCangler]

Thanks for your help with this. The cruise controls currently do NOT work.

 

[Heavy_GD]

make sure someone hasn't unplugged them in the harness trying to stop the horn.

 

[NCangler]

I wanted to follow up to let everyone know how my horn situation was resolved. I replaced the horns and then the horn bladder in the steering section (on top of the air bag). Success! Horn works great now and the Excursion has passed inspection.

Thanks for the suggestions by the members here. Have a great weekend!
Randy

 

[NCangler]

Now on to figuring out the cruise control and possibly figuring out the wiring mess that was the alarm system. Fortunately I own a 2004 F250 6.0l diesel and I think the wiring should be very similar.

 

[Hydro]

the horn control circuit is on the same wire as the cruise, so partly working already -- single wire control -- variable resistance switches
could be the brake pedal switch -- I think the pressure switch is only for the trailer brakes

 

[voodooridr]

The switch on the master cylinder is the cruise control deactivation switch

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