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MG MGB Technical - No horn

When my car was inspected yesterday everything except the horn worked fine...luckily they didn't check the horn, I did. With the key on and the horn button/rod pushed, there is a clear noise coming from the horn. But, it's not a horn, it's more of a click like contact is being made. I cleaned off the connections with sandpaper, but it still doesn't work. Any thoughts on what might be the problem?
Regards,
Randy
1977 MGB Tahiti Blue/Tan
with twin SU's
randy olson

Your horns sound like they've died. Not sure about B horns, but the horns on bikes I've had, did have an adjuster screw which can sort out some noise - might be worth a look, if not beat them with a large hammer.

My B made a very tired/quite sound from its horn when I bought it so. Rather than replace the horns, I popped a couple of air horns in there and nobody can say they didn't hear it.
S Longstaff

Randy,

Easy enough to track. Check gor voltage at the horns themselves when the horn cover on the steering wheel is pressed. That will immediately tell you where to search out the problem.

BH Davis
BH Davis

Problem is solved for now...the Prince was lurking under the bonnet! I think it must have simply been a corroded connector, or something similar. I took the car for a spin and tried the horn several times while out. Surprisingly, it worked! I must have jostled something and now it's back to normal.
Don't you love these cars?
Thanks again,
Randy
1977 MGB
randy olson

More likely that the battery voltage with the engine off is too low to operate the horn and while running the voltage rises to 14+ volts which is enough to work the horn.

I would get a new pair of horns!
Chris at Octarine Services

Had similar problem when I first got my B. Cleaned all the bullet connectors up front and solved head light issues and horn issues. Mine sounds fine with the car not running. Seems to be plenty of power with just the battery. Plenty of things to spend money on versus something you don't relly need to replace.

Best regards,
Doug
DT Toms

Thanks to all!
My philosophy is that if it's not broken, don't fix it. The horn works now, with cleaning the connectors, and turning the car on...which is when you need a horn, I think. So, I may put in another horn in the future (the air horns are pretty cool), but for now I'm going to go with the original equipment and try to keep it working.
Thanks again,
Randy
1977 MGB
randy olson

I'm having a little trouble figuring out a horn problem on my 1977 MGB as well. Push in the horn button and "nothing" If you short out the horns themselves at the horn they work. Can't quite track the problem down. If the experts out there can talk me through I would be greatly appreciative. Fortunately, it's the only thing on the car not working but it sure would be nice to "toot"!
JCH Hibbard

Hi - have you looked at the spring connector which rubs against the ring on the back of the wheel boss? If you take the shroud off, you can see it and the electrics in that area become fairly self-explanatory - just a thought... good luck!
Martin '61 Frogeye & '59 A40 Farina

JCH

what do you mean by "short out the horns themselves"?
Dave O'Neill 2

Same problem with my MBG. It was the horn push with to mutch resistance.
Solution: switch your horn with a relais.
My horn now blows like a foghorn on a ship!
Look at http://home.zonnet.nl/carclub.ij-v5/mg-ijv2.html
wim

Like Dave 'short out the horns' doesn't sound right, I assume you mean connect the purple/black wire to ground. If indeed that is what you are doing and they work then the problem is in the ground path through the column, horn button, wiper on the column casing, and the purple/black wire through various connectors.

If you put a volt-meter on the purple/black at the top of the column you should see 12v. If you don't there is an open circuit towards the horns, probably at the connector where the main harness joins the column harness, that is the only one there is.

If you see 12v, press the horn button, and it *should* drop to zero and sound the horns. If it drops to zero without sounding the horns then there is a bad conenction in the previously mentioned path.

If it doesn't drop to zero, or only goes part way there, there is a bad connection back through the button and column ground. My 75 V8 had bad conenctions in both, so to reduce effort I opted to fit a relay, which will cope with a much poorer ground than the horns themselves with.

However the 77 model year and later had 12v fed out through the horn button the the horns, and the horns were grounded through their mounting bracket. These are one-wire horns, the earlier type are 2-wire. These would need a jumper wire between the purple fuse and the horn terminal to sound.
Paul Hunt 2

This thread was discussed between 08/07/2007 and 19/07/2007

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