I need a fuse box diagram for a 4.9L F150 1995. I don't have one, and 3 of them are missing.
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I also would like to know which wire goes to the fuel pump in the tank. I think it's the brown with white stripe. Is that correct?

A wiring diagram would be nice.

I can put gas in the air intake and the engine will try to start for a second. I think it's not getting gas.

I figure my next step is to see if electricity is getting to the pump.

Any suggestions appreciated.


~~ Nehmo

 

 

I have removed the fuel pump, and it doesn't make a sound even when a battery is attached directly to it. But there is a peculiarity in the circuit to the pump. The wire is always hot even with the key in the off position. I'm speculating that this may have been the problem. Perhaps being always on destroyed the pump.
So, in addition to replacing the pump, I have to figure out what's wrong with the electrical circuit. I suppose it could be the key switch or the relay.
Again, I thank you for the help so far. Please expect me to ask the next question, whatever it is, soon.

`~ Nehmo

 

The key switch (Ignition Switch) would not do it.
It would have to be a bad fuel pump relay.

 

I'll check that (the pump relay) as soon as I get a ride out to the truck, maybe tomorrow. But thinking about it, relays usually fail in the open position, don't they? It has to be something, though.

Thanks again.

~~ Nehmo

 

The contacts on a relay can weld shut and stay closed.

 

Why, yes, that's a plausible mode of failure. I must compliment you, everything you say is logical.
I'm waiting right now for a ride to the truck. It's driving me crazy just waiting.
According to your pic, the relay containing box is in the engine compartment on passenger (right) side. I'll find it, wherever. I know the other relay box is under the dash on lift side of steering column, but that doesn't contain the fuel pump relay.

~~ Nehmo

 

The engine compartment fuse/relay box is on the drivers side (Left).

 

I'm almost through. I installed the fuel pump, but I broke the wire right where it comes from the fuel level sender. I can't repair it. I also broke another wire on the top where the wires come out. I abandoned the level sender, and I'm only using the wires to the pump. I need to bring a jack to the truck so I can lift the tank into position so I can put the nuts on the bolts of the straps. Sorry for the detailed description of events. I'm not a regular mechanic, so everything I do is apprehensive. [p]
Another thing. The screen envelope that attaches to the plastic pump container is gone. I think it was gone on the old pump in the tank. It's possible I knocked it off while removing the old pump, but I doubt it. I should have taken the screen from the junk-yard pump. I forgot.[p]
[p] I did test the new pump. It makes a buzz unlike the old pump which didn't make a sound.
~~ Nehmo

 

Any auto parts store sell the pick-up screen that goes on the bottom.

 

I installed the junk-yard fuel pump, which has its own screen on the pump itself, in the tank in the truck. When I attach it eclectically, I hear a buzz. (But there is still a problem of the wire being always on, even with the key in the off position.)

I tried to start the truck, pouring a couple of ounces of gas in the air intake. And it started, but then went off like it ran out of gas.

I suspect the fuel filter is clogged too. That's my next step. Find the filter. Where is it? I suppose it's under the frame on the left side of the truck. Is that right?

And where in the engine can I test to determine if fuel is coming from the fuel pump? And is there a connection in the fuel line I can open somewhere to test the pump output?
One more question. I didn't find an engine-compartment fuse box. On the left fender there are 2 cubical plastic things connected to wires. I think these are relays. So which one is the fuel pump relay?

I'm pretty sure I can get a ride out to the truck today.
I thank you again for your help. You're the only thing that makes me feel confident I'll be able to get this truck running. I figure, How can I fail with a person as knowledgeable as subford helping me?
~~ Nehmo

 

Does not sound good for the computer.

Yes under the frame near the drivers door.

On the fuel rail there is a small Scharader valve you can hook a fuel pressure gauge on to check the fuel pressure with pin #2 shorted to pin #6 of the EEC Self-Test plug with the key on but you will not have to short them if the pump is running all the time.

Yes they are relays. The fuel pump relay has a green base and the EEC Power relay has a brown base on older trucks.

Are you sure you are working on a 1995?

 

Am I sure it's a '95?
That's what I've thought. That's what the owner says, and he has the title. I'll double check that today if I can (that's if I can get out to where the tuck is). I'll look for the VIN and see if it says 1995 or something. ... Just called the owner. Now he's saying it could be a 1991. I wish he had told me that sooner. Or I should have been more attentive to the year. I'm upset at myself. All this time I've been thinking it is a '95 (and I never checked) and it probably is something different.

OK, that's the next step. I have to find (look under left frame) the fuel filter, remove it, and test it.

I also will check the green-base relay.

Also, (and this is unrelated to the problem we've been discussing) I have to add brake fluid. One other item I repaired was the front right brake caliper. I replaced it with a junk-yard one. When I replaced it the new one, it didn't quite go in as loosely as I would have liked. I think I need to apply the brakes to get it to seat better. And for that, it needs brake fluid, which is now drained away.

~~ Nehmo

 

I went out to the truck again. I unhooked the fuel filter (starting with the line going from the filter to the tank) and the first thing to happen was rust colored gas leaked out of the filter can. I ran gas through it by first blowing backwards and then the correct direction. I'd pour some gas in the filter, then I'd connect a rubber hose to it and blow air from my lungs. I managed to clear it, I believe. But at that time, I didn't have the cables and other things to jump it. I think it will work now.
~~ Nehmo

 

Went out the truck again. I think the newly-cleaned filter clogged just a minute after starting. I'm adding a new in-tank small screen and a new fuel in-line filter. The had to be delivered to the parts store. I'm working on it again today. I'm providing a blow-by-blow account partially for myself and partially for others to show sometimes repairs take forever.
:-)

~~Nehmo