Fuel pump blowing fuses

The ECM on the jimmy, is located on the passenger side fender well by the overflow tank. But before replace the ECM, inspect the fuel pump and fuel pump relay. The ECM sends power to the fuel pump relay and if the relay has gone bad will cause the fuse to blow which will kill the the power to the ECM, in turn kill the electrical power to the ignition system.

Start by removing the fuel pump relay and swap it with another relay and see if the fuse will blow again, if is does. Disconnect the fuel sending unit wire harness at the frame and see if the fuse blows again, if the fuse stays good. Chances are your fuel pump has gone bad or the fuel filter is dirty/clogged causing your fuel pump to draw more amp and will need to be replaced or the wire harness from the frame to the sending unit has a short which is common on older Jimmy's.

Here is a link to the electrical harness throughout the Jimmy.
http://www.compnine.com/index.php?t=...lid=6872&uid=1

go back to main fuse for fuel pump under hood

you've mentioned you've replaced the fuel pump, but the question is is the fuel pump getting any current from the battery or fuse box?

u have to test and check the wiring harness and connections from to fuel pump to fuse/relay also ignition switch harness check the connection at the fuel pump first for chaffing

Here is a link to your fuse panel. The fuel pump is controlled by the ECM through the fuel pump relay which is located on the firewall by the brake booster.
http://ww2.justanswer.com/uploads/ZZdaryl/2009-12-20_014123_fuse.gif
Thank you for using fixya, and good luck

fuse in the fuse box. also the power to prime the pump starts at the oil pressure switch. check that out too. then the relay for the pump in that order

double check all the electrical connections make sure there are no kinks in the fuel lines check all the fuses. possible a defective pump. stay away from airtex fuel pumps very high failure rate I had to replace 3 before going with a delco.

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

It's a single wire terminal with plastic connect sensor from the engine block.


This switch serves two functions.

1) provide oil pressure reading

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

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

ECM1 fuse blow is because the harness is grounding/shorting.

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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.

First if there is no sound coming from the fuel pump always look in your fuse panel for a blown fuse. If a fuse is blown for the pump if it is electrical you should hear the pump kick on when you replace the fuse and turn the ignition. If there is no sound and the fuse isnt blown then you have a faulty fuel pump.

That fuse provides power for the fuel pump. Either your fuel pump is blowing the fuse or there is a shorted wire.