'89 F250, 5.8L, dual tanks

I was having an issue with the fuel pumps not pumping fuel, but I could hear the high pressure pump (brand new), and both low pressure (in tank pumps running. Verified each one by getting under truck and listening to the tank. So in the process of checking each pump I was following a tip suggested here to disconnect the high pressure pump's wiring, so as to not run it while dry, and verify that the back pumps are not only running, but are also pumping. So I disconnected the harness to the high pressure pump, and pulled the supply line for the back tank and stuck it in a bucket to catch the fuel. When I turned the key foward to power the rear tank pump, I heard a pffft (like a fuse blowing) and there was a little bit of white smoke under the hood near the battery/starter relay.

Now I get no power to any of the fuel pumps. Car still has power everywhere else. I can crank the car and it will try to start, but obviously it wont because no fuel is being pumped. The car has power everywhere except to the pumps. Where do I look? Starter relay is fine (I assume), as I can crank the engine from the key. Does the Fuel pump relay tie into the starter relay? Would a problem with the starter relay affect power to the fuel pumps? Where is the fuel pump relay? I swear I cant find it. I checked the fuses under the dash and they are all fine. I dont know where to look.

 

power distribution box drivers side under the hood behind your air filter. bunch of fuses and relays. check your manual to see which one the fuel pump relay is

 

Sounds like you had the wires to the high pressure pump shorted to ground.
What you did was burn open a fuse link "M" that comes off the battery side of the starter solenoid.
Just try pulling each one of the fuse links apart and the one that stretches is bad.

You do NOT have a "power distribution box drivers side under the hood behind your air filter".

Your fuel pump and EEC Power relays are in a row on the drivers fender.



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By the way here is a wiring diagram if you need it:


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Wow thanks for the quick responses. I think you are right. One of the fusible links is really stretchy. Do parts houses carry these or do I need to see a dealer or junkyard?

Thanks
lopitt85

 

Just go to auto parts store and buy a roll of 20 GA fuse link wire and splice it in about 3 to 6 inches with butt connector and a ring terminal.



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Thanks. Repair done, power restored. Now I just have to drop the tanks and replace the pumps.

 

i have a box under my hood that is clearly labelled power distribution box. so does a buddy of mine with a 92 4.9L

 

Yes you and your buddy do but the OP does not.

 

oh. they must have started it with the 92 model year then. sorry for my mixup

 

Yes I think 1992 was the first year for the box.