MOT failure...

The other day my campaign failed its mot due to the horn not working…

on checking it over i found that by taking off the earth lead on one side allows the other horn to work an vice versa, but with both earth leads connected neither horn works

To be honest this has baffled me, if anyone could shed some light on this i would be very happy…   

cheers

steve

Could be not enough power to work both from live feed, you should be able to get the MOT with one working though and fix the problem later. I'll check my wiring diagram to see if i can come up with a permanent answer  

Mines currently running with just one connected. It played up occasionally and of course did it (or not as it turned out!) when the MOTs tester tested it.  Turns out mine had an incorrect set, one ?snail shaped? and one round flat type. It?s supposed to have two ?snail? shaped ones, one hi-tone and one lo-tone. Makes me think someone had the same problem before me and swapped them around to get it to work? :dontknow:

Still haven?t had the time to find another proper set yet at scrappers, apparently many up market VWs and Audis used the same setup in the 1980/90s.

You could also try a different relay and also check the earth strap at the bottom of steering column is intact, due to its location it gets very and drops off.