Any suggestions on where to start with this guys? When it rains or stays foggy & damp for an extended period, the electrical in my truck goes batty. Often won't start, but the radio will "turn on" by itself and run down the battery. If it does start, power windows may or may not work, radio still has mind of it's own. Eventually dries out and all is well till next rain. Find myself heading for cover when I see a rain cloud. Thanks.

 

To give you a starting point look at the generic electronic module (GEM), its located under instrument panel behind headlight switch. Reports are W/S leaks causing corrosion on terminals. Remove and inspect for evidence of moisture, if present have W/S resealed.