Hopefully someone will be able to assist. I have a 2005 Fiesta 1.4LX  and the other night (0430hrs) the horn started sounding continuously, how to annoy the neighbours… I don’t think it was the alarm as no lights were flashing and the sound was continuous. Thankfully it stopped of its own accord after I opened the doors and bonnet.

We drove it the following day and parked up, but when opening the door the horn sounded again and wouldn’t stop - I took off the battery lead. A nice man from the RAC then crawled under the car to disconnect the horn leads. I now know where the fuse is for future reference.

I’ve had the car into an auto-electricians who couldn’t find a fault, they tell me that the alarm horn is at the rear of the car but the offending horn is under the near side headlight. They suggested it may be the ECU which would cost more than the car is worth(?).

Sorry to ramble on, but any advice would be gratefully accepted.

 

Thanks

Tom

Probably not ecu. Probably bcm / gem .  Depends how ‘ properly’ you want to do it.  If it was mine I might be tempted to just rewire the horn from scratch.   The mot test manual does not say the horn has to be operated from the original button the car maker installed. Not ideal I know as in an emergency your instinct will be to press the original button 

Thanks for this, never thought of rewiring. I’ve had a word with my MOT man, and auto-electrician, and that’s the way I’ll go.