MGB Register Forum

Have an issue with my (car) horn!
Started going off continuously whilst driving. But it's only sounding on one! It's a 1978 and horn is on the RH stalk. I did fiddle with the wiring underneath the steering column and it stopped. Any ideas? I guess I will need to take the cowl off the steering column first so I can take a look at whats going on with the wires. A drawing of the horn switch would be useful (not a wiring diagram!)
Thanks.

I have an earlier horn button in the middle of the steering wheel so can't help with anything specific, but the horn operates by earthing a wire and making the connection, so almost certainly you will find a broken wire or some bare metal making a contact when it shouldn't!

Ian F

Like Ian, my car has the horn in the steering wheel centre. If you remove the cowling that covers the column switches, usually four philips screws underneath the cowl, it will come off as a top and a bottom part. You should then be able to get a look at the wires. At some point around 1978 the wiring for the horns was altered so that the horns are earthed and there is a live feed from the button to the horns. I don't know which way round your car will be wired. In either case you need to check the purple and/or purple/black wires carefully for any possible bare areas that could cause short circuits.

If only one horn works you need to carefully check the wiring at both horns as they are linked together, but it may be that after 40 years of being blasted by rain and road muck the horn itself has had enough! They aren't used much and the internal parts can seize.

A cheap multimeter is really useful for simple electrical checks. If you don't have one they are available for around a tenner. You don't need anything fancy.

Thanks Mike, a much more comprehensive and helpful reply!

Ian F