2nd Gen Non-Engine/Transmission Rain induced (I guess) electrical problems

[Loghead]

See if anyone can give me quick guidance as to where my problem may be.



I hadn't driven the truck ('97 2500 4x4, auto) in three or four days, it's been raining for the last two days or so; I drove a few miles and all was as usual, then, the transmission starts getting funky, the check engine light is flashing intermittently and the tach and speedo act like I'm flying over the Bermuda Triangle, alternator gauge is below normal. I figured that the alternator is wet and the resultant low voltage is driving the computer into fits. I checked the alternator and it seemed quite dry, so now I'm wondering if there are places prone to leaking at the base of the windshield or underhood where a bulkhead connector is being compromised.

A few miles further down the road and the truck straightened out and ran fine.



Any help in finding the source of this leak or whatever is causing the problem would be appreciated.

 

[tp0d]

A good place to start would be your PCM, located on the passenger side firewall. Get some Contact Cleaner from Radioshack (good stuff), take apart the 3 connectors, and hose em down. Follow any grounds, and make sure you have a good connection there. Also try removing your battery terminals, and clean em real good. .



good luck



-j

 

[DieselDoghouse]

I'm making a guess here but the NEXT place is the crank angle sensor: its low and gets alot of road assault. It is critical to engine speed indications and maybe through the PCM, speed indications. Its already been reported to be a part of charging system errors because it provides the PCM with the vital info that the engine is running and charging is possible!

 

[Missouri Mule]

While you have the contact cleaner out spray the engine speed sensor connector( also know as crank speed sensor) , make sure the pins are not bent or loose. It is located above the engine speed sensor which is located near the vibration damper. I don't think the engine speed sensor/connector will cause all your problems but has caused some of them and it is good preventive maintenance.

The PCM connectors have a better chance for moisture problems.

You could check and spray relays/connections in PDC.

 

[mcandies]

I know it has been over a year since this thread was posted, but did you find out what the problem was? My 98 12 valve is doing the exact same thing and I am about to pull my hair out trying to find the problem.

 

[scotmartin]

I would try looking at all ground connections.