Alright help me out, I have a 1988 F150 4.9L with a single fuel tank. I was driving it the other day and the truck cut out while I was going up a hill. I back it down the hill and I couldn't hear my fuel pumps turning back on. So I figured the fuel pump went bad. I had it towed back to my house and dropped both fuel pumps and tested them individually and they work. My guess is the fuel pump relay is messed up. But tried starting the truck today and all I could hear is the ignition clicking for one second and all the power is cut to my truck. In order to get powers again I have to disconnect the battery cables and reconnect them. But the truck still doesn't even try to turn over. I don't understand what it is. Help me!!!!!

 

Sounds like bad battery cables, their connectors or the battery itself.

When you get it to crank and you have no running of the fuel pumps for one second when you turn on the key check the wires and fuse links at the starter relay battery side.
If they are OK check the wiring under the relays and check for power on the big yellow wires to both relays.