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Having a problem burning up fuel pump relays on a 7.4 lit. motor. Do you think it may be the oil pressure sending unit that is tide into the fuel pump relay

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  • Anonymous Dec 29, 2008

    i HAD THE SAME THING



    I WOULD HIT A BUMP AND TRUCK WOULD DIE



    I TRACED A WIRE RUNNING OVER THE RIGHT SIDE DRIVERS SIDE OF THE ENGINE AND IT WAS BUMPING AND CAUSEING THE RELAY AND EM2 FUSE TO BLOW

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No I think you will find that the fuel pump is drawing too much current.
Also chech that you have the correct relay fitted, should be about 30Amp.

Posted on Aug 02, 2008

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Fuses


The first thing you should do is to locate the oil pressure switch/sending unit.

This switch serves two functions.

1) provide oil pressure reading

2) disable the fuel pump relay in event of oil pressure loss.

===

When this switch is failing to provide the correct pressure to the ECU. The wiring harness can overheat and eventually create a short.

ECM2 fuse blow is because the harness is grounding/shorting.

===

DO NOT drive the truck until you change the oil pressure switch.

After you change the switch,you should spend sometime to inspect the wiring between the fuel pump relay,ECU and fuel pump.


Please post up day on the comment window/page.

I will follow up on it later.


Good luck.

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