Electrical fuel problems...
 

Hello, I have been having problems with my 1989 F-150 5.0 liter V8. It is the 4wd extended cab with the dual tanks (front tank is removed).

I was driving and the truck would die like it was out of fuel, it did this intermittently until one day it wouldn't start again.

Started checking for fuel issues and did not hear the front fuel pump kicking on when it's supposed to prime.

Replced high pressure online pump and fuel filter right in front of it.

I still do not hear the pumps kicking on.

Replaced fuel selector switch

replaced tfi module

checked inertia switch

truck will crank but won't start.

will start with starting fluid in throttle body and then dies once it dissipates.

You have a fuel pump in the gas tank. The twin tanks on some of the trucks even had a third pump on the frame. Before replacing it though, there is a relay that starts the fuel pump. I'm trying to remember working on my Uncles 89 but as I recall, it's on the drivers side towards the front of the engine bay. It's a 12 dollar part and I would replace it before having to drop the gas tank. If you do have to drop the gas tank, replace the pump and the tank sending unit along with a NEW locking ring. It'll save you a bunch of grief later.
Relay
http://www.rockauto.com/info/154/RY4...mary__ra_t.jpg