Mechanics

MERCURY MOUNTAINEER FUSE PROBLEM

2000 Mercury Mountaineer • 186,000 miles

I have no fuel going to the engine. I have already replaced the fuel pump, fuel filter, and the fuel pump relay switch. I checked the continuity from the wiring harness to the pump and that checks out. I am receiving only 5 volts to the pump. Is this right? What else can I check?
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Mgraham25
December 15, 2012.



You need 12 volts. Check as it will give 12 volts for 2 seconds with the key on. Wont turn on till engine cranking.

Assuming you checked the fuse, check the inertia switch on the right lower kick panel as well.

Roy


ASEMaster6371
Dec 15, 2012.
I checked the inertia switch and has not tripped. That is all I have check on that thus far. I have replaced the fuel pump relay and according to the owners manual that there is no actual fuse. The relay is the only fuel related item that I saw in the diagram on both the interior fuse panel and under the hood. The wiring diagram that I have also only relates to the relay and no fuses. What else would cause low voltage going to the fuel pump?


Tiny
Mgraham25
Dec 15, 2012.
Yes there is a fuse for the relay. I sent you the wiring diagram.


ASEMaster6371
Dec 15, 2012.
The fuse checks out


Tiny
Mgraham25
Dec 16, 2012.
Did a continunity test from the relay to the inertia switch, and that checks out with only.1 ohms. Ran a jumper from the battery to the pink and black wire to the fuel pump and I have pressure. I have 12 volts to the #3 port on the relay. I switched out relay switches, and nothing seems to be working. Could it be in the anti-theft system? Or the computer?


Tiny
Mgraham25
Dec 16, 2012.
Ok, never-mind. It was the anti-theft system. Up and running just fine now. Thanks for your help though.


Tiny
Mgraham25
Dec 16, 2012.