In 2012 I purchased a 1988 Ford F250 XLT Lariat, 460 cid (7.5L), fuel injection, 4X4. In a span of three years I have spent approximately two thousand dollars attempting to correct a fuel delivery problem that I was having with the truck. Both my fuel mid-tank and rear tank has a low pressure fuel pump that’s activated by the drivers’ side fuel tank selector switch. When the low pressure fuel pump is activated it delivers fuel to the reservoir, then to the high pressure fuel pump, to the fuel filter, up to the fuel rail, and into the injectors. Over the last three years the truck has stopped running numerous times due to the lack of fuel being pumped to the upper rail. It was discovered that the low pressure fuel pumps in the tanks were burning out. I replaced the entire fuel delivery system several times, and the problem continued. Several auto mechanics including the local Ford Motor Dealership could not find any defects in the electrical, vacuum system, and computer. They did make a profit by charging me for parts and labor without fixing the problem.
This is what I (a non-auto-mechanic) did that fixed my truck, and now runs great. I removed both the low pressure fuel pumps from the tanks and replaced them with a 4” fuel line for fuel pick-up. I re-plumbed the delivery fuel lines from the tanks to an in cab manual fuel selector switch, and then a single fuel line to a plastic Napa fuel filter. The single fuel line then by-passed the reservoir connecting to the high pressure fuel pump. All direct fuel lines and return fuel lines were removed from the reservoir. The “single return fuel line” from the upper fuel rail was re-connected to the return fuel line on the mid-tank. CAUTION!! DO NOT USE BOTH TANKS, OR OVER-FILL WILL OCCUR IF FUEL LEVEL INDICATORS ARE NOT WORKING. USE ONLY THE MID-TANK TO PREVENT THIS FROM HAPPENING.

 

Your original problem is very common and very easy and cheap to fix. Your fuel pump relay has an electrical amperage regulator in it...when they go bad, your fuel pumps are getting full battery amperage and their life expectancy drops drastically, sometimes they burn out immediately after replacement but more often they die steadily, giving you low fuel pressure at the rail. New fuel pump relay is like 10 bucks and 30 seconds to replace. Glad you got it going another method though.

Your computer will throw a code for the amperage regulator malfunction, dealerships and mechanics love this problem because it keeps feeding their bank accounts.

 

Those low pressure pumps are in there because electric fuel pumps as a rule don't like to "suck". They push fuel MUCH better than they pull, and having to suck the fuel from the tanks will shorten its life.

 

The fuel pump relays were replaced 4 times and the Computer was tested twice. The Reservoir was changed twice. I have been round and round and nothing worked. Now my truck runs great and has been for almost 8 months. I think my truck is a one of a kind.

 

I made up all that mumbo jumbo regarding an amperage relay. There's no such thing!

Didn't fool ya, welcome to the forum.

 

Low voltage is what burns them up. Most of the time on a 1989 it is the wiring under the fuel pump relay socket. Most just upgrade to the newer stile relay and socket.
But it could have been any plug or wiring going to the pumps.