Hello all,

I have posted this problem before but now im worried. When it rains, my trucks electrical system flips out. First, in park, my radio works fine. If I either shift out of park into R-N-D, or turn on my Headlights, the radio cuts out. It will only stay on in P or N. When Im driving, My 4 x 4 light blinks without it being on, and the windshield washer fluid level indicator blinks at the same time the 4 x 4 light does. Yesterday, I had my wipers on and they would cut off for sometimes more than a minute and with them would be the 4 x 4 light a washer level light as well.....As soon as the 2 lights returned, the wipers returned as well. My rear wiper hasnt worked since the last sunny day here. My truck will not go into 4 x 4. Im at a loss here.....

Help please.

Ciph

 

It is your GCM (General Control Module) that is under your dash by the fuse panel. Feel under there to see if it is wet or damp from a possible windshield leak. Mine did it last year and I had it fixed, it was about $200. The technician said that their was no leak that it just happens sometimes and is somewhat common. I told him that their must be a leak and he insisted that their was no leak. It is either called the GCM (General Control Module) or ECM (Electric Control Module). Mine did exactly what yours is doing and it was right after a big storm. Good Luck !

 

Any low voltage electronic circuit can be scrambled temporarily, or permanently,by high energy bursts from lightning, shorting transformers in power poles or neon signs. Some times your computer, or other processing modules will be affected by this. This from a former EE who discovered the problem while perfecting the ABS system for Chrysler while working at Bendix Corp back in the sixties. Though usually shielded in autos, mechanics can fix one part of your car and accidentally ruin another with this random with high energy bursts from welders, test equipment, etc. Have all systems checked for function by the dealer. It's either the sensors or the processors of the sensed signal that is malfunctioning. Knowing which is at fault can save you big bucks.

 

Cipher, you do not need to go to the dealer for this, any competent automotive electrical repair place can do this. It is advisable for them to run a test to confirm which part is malfunctioning but I am 99.9% positive it is your GCM ! Good Luck and let us know.

 

I have been having the exact same problems on my 1999 F250 light duty supercab 5.4 4X4. It was driving me crazy since I just bought it a month ago and it had no problems. Then after a rainy spell it was acting up. The headlights would turn themselves on and off. It would try to start when the engine was already running. It would try to start whan the keys were in my pocket. ( no auto start on veh). The gauges would spike on start up, the radio would cut in and out at random, although there were times when I could make it cut out by shifting from N to D. If I was driving down the road and the radio cut out I would shift to N then back to D and it would come back on.

Last weekend I ran silicone caulking around the windshield edge under the rubber seals, since I detected water inside at the bottom of the fuse panel.

I thought I fixed the problem. It rained and problems are back. Last night I removed the fuse panel and the rear portion where the two 40 pin plugs attach. There was standing water and some rust stains. The two 40 pin plugs go up into one main cluster of wire that is wrapped in tape. It goes right up to the base of the drivers side A arm pilar then across the front of the dash before exiting to the engine compartment (somewhere) I haven't gotten that far yet. The water was just following the wire harness and its all down hill to the fuse panel.

I blew all water out of the two big connecters and dried out the fuse panel. My next step is to have windshield removed and the seal inspected and then have the windshield replaced with extreme care that the seal is maintained. I saw water in the crease of the windshield last night before working on the truck. I could see it where you look at the VIN through the windshield.

I heard that if the windshield is replaced at a low budget shop they may have difficulty with the seal due to the curve of the glass. My glass looks like it was replaced at some point so they may have screwed it up.