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Discussion Starter #1
What a day! Wife tells me this morning that her brakes are bad so I checked and decided to let her drive my truck to work today. 4pm and she goes to leave and calls me to tell me that the truck won't start. So I said to give it a little gas and it should start. She says still no start. So I drive with her car, and let me tell you that was crazy (car only stopping with one tire...:scratchhe) so I checked for spark when I got there and has spark, checked the fuel vavle and no gas. The fuel pump was replaced by fords in 2004. It has about 60,000 miles on it. Fuel gage is now pegged which makes me believe its a ground issue. I will check it for power in a little bit as soon as my buddy gets here, but meanwhile I will start on the wifes car as I got her a new master cylinder. What I am asking, if there is a ground for the fuel pump(I know there is) and where it might be located. On my old 86, I know it was connected to the battery but I don't see it there on this one. But it could be. I have check all the fuses and the inertia switch too and all seem good. Needless to say I have both vehicles down right now and hoping this can be resolved before I have to go to work tommorow....:rofl:
 

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Discussion Starter #3
New question: How many volts does the fuel pump get when the key is turned? It seems to only have 4 volts then drops to 2 volts. This doesn't seem right. Gas gauge is pegged, got the truck home and looks like I ain't going to work. I don't want to think that the pump went out but if maybe I do have a bad ground could this cause low voltage showing on the meter as well?
 

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Satyr of the Midwest
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I think you've found the problem. There should be full battery voltage applied to the pump once the relay is closed by the PCM (when you first turn the key on and while the engine is running). Bad grounds won't cause you to not have battery voltage, but bad wiring connections will. Check the integrity of the wiring leading up to the fuel pump relay, and I bet you'll find the problem.
 

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Discussion Starter #5
Is the gauge also controlled by the relay? My chilton doesn't even show the gauge. Shows the pump though.
 

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Satyr of the Midwest
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NO, the gauge and the fuel pump relay have absolutely nothing to do with one another, other than the fact that the wiring for both are probably contained within the same looming running to the fuel tank.
 

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Discussion Starter #7
Thats what I thought. When fords installed this pump they did splice into the harness. I found out about a year after they put the pump in. Because I broke down. They did a crappy job and only crimped the wires together and the salt and water corroded the wires, left me dead like I am now. But I went ahead and respliced and heat shrinked them and wrapped alot of tape around the connections. I pulled the tape off tonight and everything looks good but I think I will start to investigate there in the morning. Is it possible for the gauge and the pump to use the same ground? Theres four wires (factory) black, yellow/white stripe, orange/black stripe, and orange. My guess is that the yellow/white is for the sender, orange/black is pump hot, black is ground and orange..... another ground maybe? The problem is that my chiltons only shows the pump x2 (cause of duel tanks f150) but no sender. Man this sucks.
 

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New question: How many volts does the fuel pump get when the key is turned?
12v.



It seems to only have 4 volts then drops to 2 volts. This doesn't seem right.
You're right.




I don't want to think that the pump went out but if maybe I do have a bad ground could this cause low voltage showing on the meter as well?
No. Get the ground thing out of your head.

Remove the fuel pump relay from its "plug" test for power. There should be a constant 12v from the hot wire (possibly yellow), and with the key on there should 12v from the ignition. You can also jump the two and the pump(s) will come on.

Also check the EEC relay next to the Computer, it should be the same as above.

Did you check the fusible link as I mentioned before?
 

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Discussion Starter #9
Did you check the fusible link as I mentioned before?
Was going to but haven't yet as I bought a faulty test light yesterday:banghead. About to go out and start the process of elimination. I'll get back. Yesterday was a LONG day. Hope today goes better:rofl:
 

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Discussion Starter #10
Just pulled codes:

Code 542 = Fuel pump secondary circuit failure: PCM to ground

????

I hope this doens't mean that the PCM is bad:whiteflag

Bronco boy: I still have ground issues in my head.
Relay has 12v constant and 12v when ignition applied. Meter at fuel pump wires shows 4v when key turned then drops to 2v. AND fuel gage is pegged pass full.
 

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Discussion Starter #12
Okay update: Problem solved:chili: The problem was at the harness plug by the tank not at the pump. Was under the truck and started to tug a little on the wires going into the plug and the yellow/white stripe wire (sender) pulled out with green corrosion....:doh0715: so I cut and spliced but only solved the gauge problem, so I tugged on the rest and seen the black wire would pull out about a 1/4 inch so I decided to omit the plug and tie the wires together. heat shrinked them and turned the key and vroooommmmmmm!:chili: So I would like to thank all you guys for the help and maybe this thread can help someone else too.:beer
 
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