Ford Repair: 2002 Ford F-150, ford f 150, carpet matting

Question
Mystery electrical problem--I have a 2002 Ford F-150, 4wd. Truck that won't shift out of park unless I turn the ignition key one notch, shift to neutral and then start it. If I shift into park when it's running, I have to turn it off, and start over. Also, windshield wipers, power windows, dome light and ignition buzzer are dead. My mechanic changed a fuse and everything works again, but the fuse keeps blowing. He's stumped, kept the truck for a couple of days and can't find the problem. Short of buying a few gross of fuses and replacing the fuse on a daily basis, any ideas about what direction I could point the mechanic?

Thanks!!

Answer
Kelly,
A water leak intrusion could cause a condition like this.
Remove the front interior kick panels and see if the carpet matting is wet under the front carpet areas after a good heavy or long rain. A water leak intrusion at the 'A' post,cowl section,roof panel or sunroof (if equipped) can cause a condition such as this by entering into an electronic module. Let me know if you find the floor matting wet or damp. Have you had the GEM module checked at a Ford dealership for function?

Drew Young
Rainchaser
Auto-Water-Leaks.com