The other day it was raining so freaking hard that I thought Noah would be floating by any time.

Get in the truck to go home and it cranked but was abnormally slow to roll over good thing it's in good tune and fires right up. Head lights are dim defrooster fan is slow and wipers are slow. Thinking the WTH??? look at gages and the volt gage is low (this can't be good).

Almost made it home before all systems degraded to the point of dead fail. speedo , tach quit, volts to near zero, all the warning lights flickering, and then engine shut off and i coasted to the side.


Wierd things have happened before with south Mississippi frog strangler rains. like walk out to the truck and the defroster fan is running. I can switch it to the off position and it stops.

For whatever reason when it rains something gets energized.

So each time I go look at the GEM and it's bone dry. even blew air in it and only dry dust came out.

carpets dry, I sprayed gallons of water on the whindshield and can not find anyplace it might be leaking even took compressed air and blew all 60 gallons of my comperssor at the glass to truck seal, nothing.

Possible gromet on the firewall????? again the carpet is bone dry.

 

I would look at ground wires under the hood and dash. Check all fuses, too. If you can examine the GEM circuit board, maybe it was fried in the past and is still haunting you?

 

That was the only part that was whooping me. For not wanting to break something I sorta gave up getting the GEM off the fuse panel assembly. I had the whole thing away from the dash and was able to sorta twist it and fiddle with it. but the 10mm fasteners that appeared to be holding the GEM to the fuse black did nothing in the way of letting loose. the two pieces. So the truck is running and I put it all back together after not finding water.

What is that thing right next to the parking brake pedal and arm assembly. Silver rectangular can, I unscrewed and pried the black plastic cover off and was able to wiggle it around. it looks like it got wet once before in a prior life. got a big wiring harness going out the back of it through the firewall.

 

Are you referring to the PCM?

 

i had something very similiar in my truck. what i found out was my fuse box was corrided. i could not tell by looking at the fuse box just split the fuse box apart and water rolled out with rust and corrision, by the way my rug was never wet ,i finally found my aftermarket windshield leakingand replaced my fuse box and have not had a problem since.

 

I had the same problem when it rained hard for more than two days i would have electrical issues. i would go out to the truck to go to work and the fan would be running. Fought the issue for over a year. I replaces the fuse block and the gems controller they both showed signs of water once i had them out of the truck. I check the windshield my self twice for leaks with water and compressed air. Had the glass company test and said it was good. Then had a bad crack in the wind shield and had it replaces and when they removed the old one you could see that it was leaking but it was so small you needed a lot a water to see it.

 

Alternator died yesterday. Might have been going out intermitantly. New unit and all is again right with the world.