On my 2001 Excursion my horn dosn't work when the truck is running, but works all the rest of the time. I have changed the clock spring and that didn't fix it. Any help would be great.

 

Maybe the relay?~

 

Is it even getting power at the switch when the truck is running?

 

My horn quit on my '01 in the same manner ... would blow only with the engine off. My cruise control started acting up, too, about the same time. I had to replace my GEM, which also meant new unlock codes.

 

I am having the same problems with my 05 EX. Horn works after I replace the fuse for 2 secs then dies down as the fuse blows. Cruise is also **** up.

cficare what is the GEM? where is it located? how much does it cost?

 

Try this bumper sticker.

 

Maybe a wire is being pinched!

 

Does it actually blow a fuse or it simply doesn't blow when the engine is running?

It sounds like it is more related to the key switch than the horn switch. The horn is wired to a constant 12VDC source and the only thing that changes is the physical location of the key switch as well as when your truck is running you have the alternator charging the DC system.

Are there other DC accessories that don't work when the engine runs? Radio, cruise, windows, door locks?...just trying to figure out if there is a common thing here.

The horn switch is wired to the horn relay and the 12V for the horn is pulled in when the horn switch is depressed/closed. So either the relay is bad or there is some other mechanism that is related to the ignition key switch location and a frayed wire in the steering column...that's why I was asking about any blown fuses.

Just thinking out loud as I type is all...

FWIW...the horn is tucked in under the passengers side fender...you can pull back the wheel well black liner and see the horn way up front...very well protected indeed...

Good luck,
Joe

 

When I first noticed I changed the blown fuse, tried the horn it worked for about 1.5sec then slowly died down until the fuse blew again. I did this 2 more times with same result. My cruise control also does not work. Everything else that I can tell works fine. If you got any other ideas let me know, I have looked through the fuse/relay diagram for my Ex and cannot find a fuse/relay for the cruise control. Thanks for the help.


QUIKKER347 sorry for "hijacking" your post.

 

Unplug the horn connector from the horn itself and replace the blown fuse and see if the fuse blows, if it does, remove the relay and try again, if it does remove the steering column and look for and suspicious wires that might be shorted.

 

Which relay are you talking about? I have only found a fuse for the horn from this list out of my owners manual.

Fuse/Relay
Location
Fuse Amp
Rating
Passenger Compartment Fuse
Panel Description
1 15A* Adjustable pedals
2 20A* Power point - floor console
Roadside Emergencies
200
Fuse/Relay
Location
Fuse Amp
Rating
Passenger Compartment Fuse
Panel Description
3 20A* Power point – 3rd row
4 20A* Power point - I/P
5 20A* Power point - right rear quarter
6 20A* Trailer tow turn/stop relay
7 30A* High beam headlamps / Flash to pass
8 15A* Backup lamps (Diesel engine only)
9 20A* Heated mirrors
10 10A* A/C clutch
11 20A* Radio (main)
12 20A* Cigar lighter/OBD II
13 5A* Power mirrors/switches
14 15A* Daytime running lamps (DRL)
15 10A* Driver’s seat module memory
16 15A* Rear seat controller
17 15A* Exterior lamps
18 20A* Turn lamps/Brake on-off switch (high)
19 10A* Body Security Module (BSM)/4x4
module
20 10A* Fuel Injection Control Module (FICM)
relay (Diesel engine only)
21 25A* Rear smart wiper motor
22 20A* Engine control
23 20A* Engine control (gasoline engine only),
Climate control (Diesel engine only)
24 2A* Brake pressure switch/Speed control
25 10A* 4-Wheel Anti-Lock Brake System
(4WABS) module, Variable Fan
Control (VFC) (Diesel engine only)
26 10A* Airbags
27 15A* Ignition switch Run feed
28 10A* EATC module/Front blower relay coil
29 10A* Customer access
Roadside Emergencies
201
Fuse/Relay
Location
Fuse Amp
Rating
Passenger Compartment Fuse
Panel Description
30 15A* Highbeam headlamps
31 15A* Transmission range sensor (then to
starter relay coil), 4x4
32 5A* Radio (start)
33 15A* Front wiper
34 10A* Brake on-off switch
35 10A* Instrument cluster
36 10A* PCM Memory
37 15A* Horn
38 20A* Trailer tow park lamps
39 15A* Trailer tow back-up lamps
40 20A* Fuel pump
41 10A* Instrument cluster
42 15A* Delayed accessory
43 10A* Fog lamps
44 10A* PATS module, Transceiver
45 10A* Ignition switch Run/Start feed
46 10A* Left-hand lowbeam
47 10A* Right-hand lowbeam
48 10A* Rear smart wiper motor
101 30A** Trailer tow electric brake
102 30A** Door locks, BSM
103 50A** Ignition switch (gasoline engine only),
FICM power (Diesel engine only)
104 40A** Heated backlight
105 30A** Fuel heater (Diesel engine only)
106 30A** Front wiper main
107 40A** Front blower motor
108 40A** Auxiliary blower motor
109 30A** Heated seats
110 50A** Ignition switch
Roadside Emergencies
202
Fuse/Relay
Location
Fuse Amp
Rating
Passenger Compartment Fuse
Panel Description
111 30A** 4WD/Shift on the fly
112 30A** Left-hand power seats
113 30A** Starter motor
114 30A** Right-hand power seats
115 20A** Trailer tow battery charge
116 30A** Ignition switch
601 30A CB Window motors, Moonroof
602 60A** 4WABS module
210 — Not used
211 — Backup lamps relay (Diesel engine
only)
212 — Not used
301 — Front blower motor relay
302 — Powertrain Control Module (PCM)
relay
303 — Fuel heater relay (Diesel engine only)
304 — Heated backlight relay
305 — Trailer tow battery charge relay
306 — Delayed accessory relay
307 — Starter relay
* Mini Fuses ** Maxi Fuses ***Circuit Breaker
Note: (Diesel engine only) The Fuel Injection Control Module (FICM)
logic 15A mini-fuse is located in the underhood relay block.

 

Look under the hood...