High pressure pump not getting power

DIESELNEEDSHELP19

MEMBER
1999 FORD F-250
7.3L
V8
TURBO
4WD
AUTOMATIC
170,000 MILES

Hello, I have the truck listed above Super Duty 4X4 it has the 7.3L turbo diesel. I was driving it when the truck suddenly shut off and now after playing the guessing game I found out that the high pressure pump wasn't kicking on. So I had it tested and it tested fine. So I put it back on the truck and still no power. So I jumped a hot off of the battery and the pump runs as long as I keep the hot jumped to it. I have already tested fuses and can't see any visible breaks in the wiring going to the pump and I am running out of guesses. Please help!

Wednesday, March 27th, 2019 AT 4:50 PM

1 Reply

JOETECHPRO

MECHANIC
705 POSTS

Hey DIESELNEEDSHELP19,

The pump you are talking about is the low pressure lift pump located on the frame rail?

I have attached a wiring diagram which shows the supply to the fuel pump.

It shows the fuse (fuse 19 under hood fuse box)

If that is okay I would check the inertia cut off switch, instructions on how to replace attached. It is on the passenger side the trim below the dash on the right hand side. There is a red button on the top of the switch. If it presses down and resets that may be your issue. Try starting after this. You should have 12 volts in on the dark green/yellow (dark green/yellow wire) If not you need to check at the fuel pump relay to make sure you have power in/out.

I have attached a description of the relay location for you too.

Check the fuse and the inertia switch and report back.

Hope that helps.

Regards, Joe

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