Won't start unless battery disconnected, then re-connected
 

I've got a 1994 B4000 that has a strong 2 year old battery. No real problems with this truck since the day I bought it 15 years ago.

Now this past month, about once or twice a week, it won't start. Won't even crank. Just dead. No electrical anywhere on the truck.

First time it happened I thought maybe a light was on overnight and drained the battery? So I disconnect battery for about 3-4 minutes thinking I'll just take the battery in to make sure it's OK since it's still under warranty/guaranty. But then I decide to just leave it unhooked long enough to reset the computer, and that was all it needed. Started up just fine. It's done the same thing to me about 4-5 times now and I would like to get the problem fixed before I sell the truck this fall.

No pattern to this at all. Sometimes it will do it after being driven, shut off, then try to start right away. Sometimes after having sat for 2-3 days. The battery is good and cranks up just like normal when it does crank. No funny noises or smells in the brief second that it does crank before it starts.

Any ideas as to what the primary cause might be?

I would buy new battery cables, and tighten them on there with a wrench after you scrape the battery posts with a knife. Buy the whole cable, not those "fix it" cable ends.