Dead battery after rain?

[pilotsareplanecrazy]

Don't worry, I feel about as dumb as the title sounds.

I picked up an '89 with 90K miles last month and it has been running flawlessly. Two weeks ago, I walked out to start it and the battery is dead. Not just kinda dead and won't crank all the way, but dead-dead. I jump it and limp to my friend's garage. I pull the battery off, charge it up, clean the terminals and posts, and put it back on. It fires right up and runs perfectly until last weekend.

I go out to the truck Saturday night and it's completely dead again. I had been paying special attention to making sure everything was off or unplugged when I got out, so I am baffled.

The ONLY similarities between the incidents is that the battery was dead the first time I started it after driving it in the rain. It has only rained two days since I picked the truck up, and the battery has only died on those days after it has rained.

Is there any way that there is moisture getting in to a fuse and causing it to drain the battery or am I just crazy? There is a large clear fuse with a green wire (is this the fuseable link?) that has a chunck taken out of the housing, but nothing looks exposed.

Anyone have any idea?

 

[lovetoski]

Right off hand I don't see how rain could be an issue. Maybe, but not likely. I'd start with the basic stuff: is the batt OK, and does it hold a charge, does the alt work OK, etc. Most auto parts stores can test all of these for free.

 

[jwest]

Nothing electrical works or does it just not turn over.
Unless you have some parasitic loss, it may not be holding a charge.

Completely discharging a starting battery (as opposed to a deep cycle battery) pretty much ruins it, or rather, it greatly shortens it's life.

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