'87 carbed PU. Think it's a CA model.
So I go to start it, and it turns over for a split second, and then nothing. The idiot lights are lit, but very, very dim, and turning on the headlights produces nothing but a buzzing from the stalk.

I leave the key on to steer, and start rolling it back so I can get out my car. Suddenly everything kicks on, and it fires right up. Drove it 120 miles without a hiccup, with several stops and cold starts. No problems.

I figure it's a loose ground or battery connection. All the obvious connections seem to be OK, and the battery is fine. Prior to being parked, it was on a long trip in heavy rain. Any ideas?
Thanks.

 

I would pull the battery cables of and clean the posts and terminals, they may look good, but they may still have a bad connection, it happened to me once

 

Already done, thanks.

There's some sort of a box (computer?) behind the pass. side kick panel. Anyone know the function of this, or problems that could arise from it?