BMW 325i 1991 Cabriolet Horn and Wiper fault I have had an intermittant fault with the wipers and horn now complete failure. Can anyone give me a qlue where to look.?

On BMWs with these type of problem, I look at two things first..

1) Replace every fuse in the wiper and horn circuit. To be honest once the car has over 80k miles or 10 years I replace every fuse on the fuse panel. If you are really cheap and want to save .50 cents, you can pull the fuse, sand the metal oxidation off the fuse and see if this helps.

2) Replace all of the relays in the wiper and horn circuits. On my 323i, the wiper relay is under the hood. Again, after 10 years those relays I would replace the relays as part of your maintenance.