Hopefully this problem was fixed for you, but since nothing is posted, AND it may help someone else out, here's my story: Are you having this same trouble AND air conditioning issues? Back in February of this year after a heavy rain, we experienced the same problem on the A1 in the dark; fuse 3 blown, and thus no fans on the climate control, no indicators, horn, etc. My mechanic found some wiring had melted behind the main fuse box, put that right, and everything was fine until Easter Sunday. Same issue: driving in a heavy rain (on the A1 again funnily enough), same failures. He couldn't find anything significantly wrong; replacing the fuse sorted the problem. It got more frequent from there. Any rain more intense than a drizzle and it would blow. He couldn't find anything. Ford couldn't find anything. So we contemplated a failure in the GEM (and replacing the fuse box, a very $$$ (sorry: £££) proposition), so we began a "testing period" to isolate the location of the (apparent) water problem. Today he fixed it. The problem had seemingly become less frequent, so we were content to continue changing the fuses about every other week, and took the vehicle in to get an air conditioning failure investigated and corrected. Turns out that a (the?) air con pressure switch had not only failed, but come apart, and water had been getting to the electrical parts of it. Replacing the pressure switch not only restored the air conditioning (after a gas recharge), but let me drive through one of the heaviest rains I've been through in a long time, with out the electrics failing. It's still doing well, and I'll update this if anything else crops up.