2006 Peugeot 107 horn not working

This is quite a common problem with Peugeots, I have a 307 which had the same problem it worked fine for years, so I took it to a main dealer who quoted over £300 for a new steering wheel or he could rewire the fault which turned out to be a loose earth wire, £45 and it works fine. Before I had it repaired when it rained the horn did not work either so I used waxoyl on the terminals to water proof it. Peugeots are designed by morons who would put a horn and its electrics just under the lowest part of the front bumper where all the surface water soaks the electrics no wonder it did't work.