Help Please! Electrical Issue

[jerseyrr]

I'm new to the forum, as I just recently got a 1988 Ranger. It was owned by my grandfather who barely drove it, has 91,000 miles and looks like new (just a little faded). I have never had an issue with the truck, always started great.

Yesterday when I went to start it, with the key in the accessory position everything was fine, but when I turned the key to the on position, suddenly the dash and interior lights dimmed and stereo went off, and it seemed as if there was a dead battery, but the battery is ok. Anyone have any ideas what this could be? I was thinking maybe a pinched wire as something is drawing a lot of current when key is in the on position but that was a shot in the dark.
thanks for any help.

 

[LearjetMinako]

The battery maybe okay, but check the battery terminals. I had this problem before on my 96 Ranger. The terminal contacts just needed a little cleaning and everything worked again. Even thou there was no corrision or rust.

 

[E4Ranger]

did ya load test the battery? It may read ok with a meter, but put it under load and may drop in voltage a good deal. if ya dont have a load tester take it to Walmart, Sears or a shop and they normally test it for free.