Rain and starting issue

[bishop10]

I ran in Walmart one rainy night and came back out to my truck not starting. 4x4and oil light stayed on. Gas mileage was going crazy, saying I had 220 miles til empty, then 0, then 680. Had truck towed home and it started up fine the next day.
A day or two later the vent would turn on full blast after taking the key out of the ignition.
Recently we had some heavy rain and the truck went crazy again. When put in park the starter would run. While driving it started to drive bad like it was in the wrong gear. I pulled over and it started itself. I turned the key back to the start position and turned it off and it started itself again. Ended up burning out the starter. The truck sat for about a week and the front driver seat floor was wet with water from the rain.
Ive read about the windshield on the 1st gen expy not being sealed correctly. I wish I had known about that the first time I had the issue...I just replaced the starter and started her up and she ran fine a good 20 minutes and all of a sudden the starter cranked again while the truck was already running. The truck had a little time to dry out, but I did not replace the GEM module or anything
Anybody know what I need to do? Or anybody else experience this before? HELP

 

[1955moose]

Had same problem with my 2000 expy, you've got to seal the window all around drivers side. I used regular black rtv silicone on mine. I pulled off strips around window and sealed basicly to middle of top and bottom , on drivers side. You may get lucky and your fuse box and gem will dry out on their own, mine did. When I saw how crazy it was to get gem and fuse box out, and with the possibly bent pins I left alone. You need to seal ASAP or this will repeat itself. Since sealing I can drive through heavy storms, with no issues. Good luck.


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[stamp11127]

Well you can have the windshield sealed, dry out the gem and plug it back up or you can move to the desert once it dries out.

Seems you have already read about the problem and know the solution. You just need to "get er done".

 

[bishop10]

I thought maybe it had dried out. It sat for days but I guess I'll have to bring it in a dry it with a blow dryer.

 

[1955moose]

I've heard Phoenix is nice this time of year!


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[bishop10]

Gem seems to be dry, however on a different thread I read that doesn't control the starter. What would be causing the starter to crank on its on. Starter relay? Solenoids?

 

[stamp11127]

Sticking solenoid on the firewall, issues on the control side of the starting circuit and possible sticking starter solenoid. I'm not able to view the diagram for yours so can't be 100% sure on how they configured the starting circuit.

 

[ExplorerTom]

Had same problem with my 2000 expy, you've got to seal the window all around drivers side.

You're talking about the windshield, right?

 

[1955moose]

My leaky windshield did cause the starter to grind while running. When the gem and fuse box dried, it stopped grinding, and my power windows and radio came back to normal. Maybe I was one of the lucky ones. It rained real hard in San Francisco last night, I had no electrical issues.


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[stamp11127]

Either solenoid sticking will cause the starter motor to turn.

What is the gear selector position in when it cranks unwanted?