I have a 1990 F150 4.9L 5-speed and when you turn the key the Fuel pump will whine away and then maybe 5 min-never will shut off and the truck will start. I have replaced the Fuel-pump,filter,relay(fuel pump), fuel pressure regulator, altenator. One morning went out to go to work and the battery was dead, tried jumping didn't work so charged it and waited for the fuel pump to shut off and battery went from 12.8V to dead in less than 10 min. So I replaced the altentor! This problem started out once in a while now it is everyday so I just stopped driving it, Sounds like a short to me somewhere I don't know can someone help!

 

Well you seem to have spent money on other things than resolving the reason the pump runs uncontrolled.
The Alternator, fuel filter, pressure regulator have nothing to do with the power to the pump.
You have to do some testing to find out why the relay is powering the pump at the wrong times.
Here is how it works; When you turn the key to 'run' the computer puts out a ground to the pump relay for a couple seconds then the ground is removed and the relay drops, the pump stops.
There is a lead from this same circuit that goes to the computer test plug so the pump can be test run for pressure testing, regulator testing etc.
You either have a permant ground on this lead/circuit holding the relay operated or the relay sticks it's contacts closed for some reason.
Find this out and you solve the problem.
1. A ground on the lead.
2. Computer fault (very unlikley).
3. Relay operating fault.
Note that the power for the pump relay is the same power for all the fuel injectors.
To test for a permant ground at the computer test connector, check the terminal located on the right side bottom row with the two seperates on the top as you look at the connector. This lead connects to the pump relay and to pin 22 of the computer.
If you remove the relay the pump should stop so you can test for a ground with the key off.

 

Here is a diagram of what he said. ^^