Ok, my truck has been acting up for awhile.. When you go to start it, the power will just completely die.. If you unhook the battery, and rehook it back up, the power is back, until you try to start it again.. The problem doesn't always happen, and sometimes the truck doesn't do it.. It's a 91 3.0 and i'm clueless here.. only thing i've replaced so far was the voltage regulator, which i thought solved the issue but it didn't.. It fixed part of the problem where the voltage gauge would be bouncing around.. The truck will only turn over on a charger/starter when the issue arises, and even then it's super slow.. I'm losing my mind here and don't want to start throwing money at it..

Thanks guys!!!

check all battery cable connections, both ends of both cables...you can either take them apart and clean them, or check them for continuity w/ an ohmmeter...if that doesn't help it have the battery load-tested

Check for a bad battery to block ground connection. Suspect you will find it green somewhere.

You can try cleaning the battery posts and battery clamps with a post cleaner or a wire brush. When that is done don't forget to to apply some dieletric grease. This worked for me, hope it helps.