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fuel system electrical info needed


I bought an 88 F-150 several years ago and my dad wanted it when it was time to get rid of it.

He has owned (driven) it for about 2 years now. It sat quite a while this winter and now has some issues. He drove it to work recently and it quit on him. I think it is fuel related (seems to have spark), so I am going to ask some questions there first.

Info: 88 F-150, 4X4, 351 (fuel injected), C6, dual tanks.

How many fuel pumps does it have and where are they located (dual tanks)?

Where is the fuel pump relay (more than one?)? Typically they are in the power distribution box under they hood, but which one is it?

Where is the inertia switch?

Once I know where to look, I will check that stuff out and make sure the pump(s) are working and go from there. I have seen ground issues stop the pumps from working too.

Any help will be appreciated,


Staff member
you will have one pump in each tank (not sure if there is one on the frame as well) the fuel pump relay, check passenger side, below the windshield area, might be a green one, and a brown one (one is pcm power, other is fuel pump) the inertia switch should be on the center hump, under the dash, passenger side.
on an '88, i think the inertia switch is near the fuse box by the e-brake. that's where mine is. my pump relay is green.


Staff member
Isn't there also a secondary high pressure pump on the frame rail as well? Don't remember what years they used them on...I do know 89 was one.
The 88's have one also. Brian, you're gonna need someone to listen to that frame rail pump (just under the driver's side door inside the rail) and turn the key on. The pump should only spin a few seconds, like 3-4. if that seems to work ok, try taking the vac hose off the fuel pressure regulator (located at the rear of the fuel rail) and try cranking to see if fuel comes out. a ruptured membrane will basically flood the engine. you'll need to pull the plugs and change the oil if it is.
Good luck, my friend!

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