Anyone have a wire diagram for the fuel pump (stock, HFCM) circuitry ? I am trying to troubleshoot no voltage to the pump and I need to know the flow between the relay, inertia switch, etc...Thanks in advance !!

 

Kinda basic, but this will help: http://www.backglass.org/duncan/ps60...l/ps60_091.jpg

 

The first diagram below is 26-2 and shows the fuel pump circuits plus a few others. The second diagram is 26-1. I put it there because it is referenced in 26-2.

 

I should mention that those diagrams are for a 2004. If your truck is NOT a 2002-2004, then the wire colors and connector numbers will probably be the same, but the fuse numbers will definitely be different.

 

great guys,
Thanks so much, so it looks like the relay in the junction box is definitely before the inertia switch. So if I have power at the inertia switch it is safe to say that the relay is working. I must have a bad connection somewhere between the switch and the pump...

 

take note of the fact the the relay for the fuel pump does not list pin numbers while the one for the heater does. the one without numbers is part of the module and can not be serviced.

 

THANKS to everyone for their help...turns out that I screwed up and had the wrong connectors on the WIF sensor and pump . They will seat incorrectly even though they are keyed. I checked the voltage at each plug when first installing but hadn't realized that the inertia switch was tripped when I did. With the switch tripped, I saw some voltage at the black plug and nothing at the gray so had figured that there was low voltage to the pump and the WIF sensor was just an open or close switch. WRONG. Wiring diagrams with wire colors showed me where I went off track. Much better now...