Horn Stuck after new battery install!
 

Battery died on Saturday. Installed new battery last night. I first connected the postive. The second the negative made contact, my horn went off.
This is a constant horn. Not the on/off-on/off alarm sound. My car would also not start up. Finally after clicking an alarm switch under my dash, I was able to get my car to start, but the horn would not turn off.
I finally just removed fuse 26 and now the Expo works, but I have no horn.
I purchased the vehicle last year from an auction, and everything has been good, until now. I believe it may be a function of the alarm installed at dealership. Should I just have the alarm removed? I have googled for hours and searched this forum without any success. Has anybody heard of such an alarm function?
Any help would be greatly appreciated.

George :-huh

Sounds like the relay for your horn is stuck. What year is your vehicle ?

Did you try locking then unlocking the vehicle with the remote? That might reset the arming of the alarm.

2004 EB EXPEDITION
 

It is a 2004 EB Ford Expedition. I tried pushing everything on my key fob, locking and unlocking manually. Even after driving for a while I tried putting the fuse back in and still the horn goes off.

George

I did a bit of searching and found this thread. I know it's for a Mustang, but since it's Ford the solution could be the same.
Replaced old battery and now cannot start vehicle. Alarm system issue? - Ford Mustang Forums

That definately sounds like my issue....Thank You. Now do you think just removing the alarm will correct the issue. In the post you linked to, the individual had the alarm fixed. At this point I just want to have a working horn and doors that unlock/unlock from my keychain.

Sure, no alarm, no issue. You will have to find and bypass the starter kill relay so that the vehicle can be used for more than just a lawn ornament. ;)

are we talking aftermarket alarm/remote start system ..........doubt a FOrd system would do that after a dead battery

I believe it is a dealer installed addon to the Ford Stock alarm?

On a side note, I had the hardest time finding the Ford Manual last night and I saw many threads with out a resolution looking for the manuals. So in case anyone is looking and hops upon this thread, you can find them right here:
https://www.fleet.ford.com/maintenan...ls/default.asp

Page 259 of your owners manual shows the horn relay to be R305, however it also says, "Note: Relays R301–R305 are not serviceable components; see your dealer or a qualified technician for assistance".

That just means do not take the relay apart and try to repair it. The relay itself just pulls out and a new one plugs right back in. However, his issue isn't with a relay, it's with the alarm signal wire that runs to the horn relay coil circuit. He has to locate and remove it.

It appears you horn relay can find ground from either the horn switch or the alarm system. If you isolate the source of the ground you have found the problem and can fix it. Sounds like it is alarm related. Does the alarm have a fuse? Did you pull it? Does the horn still sound. Pull the horn switch fuse. Does the horn still sound? Have you swapped the horn relay with a known good one? You can procede like this.

Thanks for this post, and for the mustang one. That's exactly what is happening to my F250 2006. But, I gotta add that's happening when temps drop under 45 degrees; yeap! sounds weird but real. I can spend in summer every night sleeping all night long, but when falls shows I have to disconnect batteries (both) to avoid jumping out of bed to not bother my neighbors with my horn screaming aloud.

We have the same problem. Have you found a fix, if so can you please post it.

Nothing yet
 

We are gonna take it to the dealer this week with some printed paper of this forum. But, we already know we have to spend some buck regarding on this matter. We just want to get rid out if this. Let see what the dealer has to say about it. I will post further info...
What's your ride? I would like also to talk about it to the dealer and see.
:-duel1

Keep in mind if this is an aftermarket alarm system the dealer is going to tell you to take it back to the people who sold you the alarm, not to mentions the cost to have a dealer work on it if they decide to help you. Ouch! This is NOT a difficult problem to troubleshoot. You can do it with a schematic and a DVOM. I'd be willing to atempt it without the aid of a schematic as long as I could locate the horn relay which isn't hard to do. If your alarm is putting ground on the control side of the horn relay the horn will sound. If you look at the underside of the horn relay socket you'll probably see a wire coming from your alarm soldered to the horn relay control side ground wire. Disable the alarm(pull fuse) to see if the horn stops. If it does you know the alarm is the problem. If not you have to see if the horn switch is shorted. Ford puts the horn switch inside of the airbag on some models. The horn switch can either go short or go open. You can't fix it either way if it is inside of the air bad. You have to remove the airbag(kill power) to get to the wires going to the horn switch which are located behind the airbag. You cut the wires going to the switch and solder on some leads. You drill a hole in the top of the steering column. You pass the leads you soldered onto the horn switch wires through the hole you just drilled Then attach a doorbell switch($5 at your local hardware) to the leads. Done! Either that or you can pay $800.00 for a new airbag which just happens to come equipped with a new horn switch. The choice is yours. I know which way I do this repair. Parts $5 Labor 1 hour.

This is not an aftermarket alarm system it is the Ford dealer alarm that came with my 2006 F250 Diesel Lariat FX4. By the way, I am a second owner and I think that was the reason it was sold since the truck it is in more than excellent conditions with 65000+ miles when I bought it. I tracked the ownership of it and was bought at first for a building company. I am really happy with this truck but the alarm is driving me crazy :-X09.

I cannot turn on the truck when the alarm started. It is a constant sound and not an intermittent one, but only happens when temps drop. It will even sound if I connect one battery (either left or right) and the temps are still under 46 for example.

I "know" (:-X01$$$) the consequences to take it to a dealer, but I already took it to another place and they suggested me to address it to them.

Sorry, I am not too proficient with mechanical specially electrical ones :-banghead, and I just came up for an answer that I think I found. The Mustang sounds pretty much familiar adding the temps of course, and apparently I am not the only one with this kind of issue.

Thanks eallanboggs.

OK! it was the horn and cost $$700+++. No problem so far with temps under 40 and still under observation, but I feel it is done. No wonder I couldn't do anything but take to the dealer. Now, I like more my truck!

$700 ? Ouch, I think I would have just rolled down the window and yell HONK for that much. :-hair

I would have fixed that for under $100 including parts($5 doorbell button at ACE hardware). I've made this repair many times(mostly on Lincoln Town Cars) and the owner is happy when they find out they don't have to pay for a replacement air bag($600 plus at dealer) to fix their horn. Some people say they don't car if they have to use a doorbell switch to blow their horn since they only blow it one time a year during the annual vehicle inspection.

I put a new battery in my trunk f-150 and the horn keeps going off if you open the door.we took outthe fuse for the horn and now the flashers blink .please help the guy who put the new one in took some thing off and said it was a add on alarm but it is off .please help me if you can't be nice don't say anything.

I once took my shoes off and my jacket unzipped itself. I'm still trying to figure that one out. Maybe it was too much Cabo Wabo?
Factory alarm; go to dealer
Aftermarket alarm: go to alarm store
or disable the alarm

Why so rude ?

$700 to replace the horn... the thing under the hood that a loud sound comes out of?

Probably the flashers were also blinking when the horn was blowing but you just didn't notice. These are both functions commonly controlled by an alarm system.
My guess would be that something needs to be reinitialized on the alarm system. It probably has some type of internal battery that will keep it in a powered state even if someone messes with the vehicle power (like disconnecting the battery).
I suggest you find the model # of the alarm and search on line for a manual if you don't already have one. It will likely give you some info on resetting the system, or take it to an installer, they probably know what to do without even looking it up.

horn sticks esp in cold weather
 

[qote=weslhg;9696330]We have the same problem. Have you found a fix, if so can you please post it.[/quote]
Had the same problem with another car a few years ago. A neighbor suggested we change the steering wheel cover for the horn. Amazingly, that took care of the problem. Seems the vinyl would contract in cold weather, creating the problem.
Just saw this post-----two months after the original post---sorry.

Ford Alarm
 

See if the solution is in this post:
https://www.ford-trucks.com/forums/1...reset-fyi.html

For Ford System 3/4 Alarms.
Disconnect the battery. Wait 2 minutes for the module to lose all traces of voltage. Turn the ignition key to the RUN position. Reconnect the battery. Shut the key OFF and press LOCK on the drivers door switch. It's called reinitializing the alarm.