lost blinker, wiper, and radio power but gained enginer performance???

I have a 1994 Ford Ranger that is displaying some weird "symptoms" so to speak. I loaned it to my grandparents a long time ago and recently got it back and instantly noticed a significant loss of power as well as the gas gauge not working.

The main problem is that I can barely climb a small hill in this thing without being in second or third gear. When I first got it 8 years ago I could climb small ones in 5th gear and pretty much any steeper hills in 4th. Well, today I was driving home from work and stopped to get some gas (since my gauge doesn't work I fill up all the time.) I got back in the truck and cranked it up and I suddenly noticed that my radio, windshield wipers, sprayers, and blinkers did not work at all and my Check Oil light and Brake Light were on (even though the brake was not depressed). The truck was running fine though. In fact, as I drove the rest of the way home down the interstate, I noticed that it was back to its old self again. All the original power was back. I drove the whole way home in 5th gear without having to downshift to climb any hills. I called my father and he was clueless with the exception of thinking that it could be a short somewhere.

I got the truck home, turned it on, and immediately began checking all the fuses thinking that a fuse had something to do with it. I pulled them all and they all looked perfect. I called my grandfather and he said he had recently replaced them all with new ones. I put them all back in and cranked the truck back up and POOF, everything worked...windshield wipers, blinkers, radio...everything (except the gas gauge still). I didn't go back out on the road yet to see if the power is gone again, but I'm guessing that whatever the problem is, it is sucking the power away from the engine.

Any ideas?

Maybe a bad ground wire connection somewhere?

I had an older GMC Jimmy that had me pulling out my hair trying to fix a bad miss. I got it cheap and the idea was to sell it for more which I finally did. Turned out that while I was negotiating the sale. The buyers friend opened up the passenger door and all of the sudden the motor smoothed right out. Closed the door and it was back to running like crap. Wish I'd have found that sooner but i did tripple my money on the truck LOL.

Fuse

There is a fuse under the dash, its labeled "stay alive" warning or something in a haynes manual, if it blows them you loose yor blinker and your brake light comes on. I had this same issue when I was changing my turn signal bulb socket I shorted out the wire.

fuse

"Keep Alive" is what is says, just looked it up. I hope this helps