Its Monday - Truck quit on way home

[DennyDay]

Truck quit on way home tonight. Jumpered aux. fuel boost pump to get it home (no lift pump noise) Can't find any blown fuses. Put A/C clutch relay in place of fuel pump relay and lift pumps work. Haven't seen anything on this problem. Is there a fuse or overheat breaker in the system? Has anyone had a similar problem? If so, what was the cause? and finally did a relay replacement solve the problem?



Thanks, Denny

 

[SEmerson]

Sounds like just a bad relay

 

[Bigsaint]

Denny, just guessing that relay in your PDC is the same as mine. The fuel system relay controls the VP44 and has nothing to due with the transfer(lift) pump. At least that's my understanding. The power for the transfer pump is provided through the ECM, there's no relay/fuse directly linked to the transfer pump.



I think the problem lies directly with one of your transfer pumps, they don't just die, they usually go out slow and maybe it came back to life after a short break. Just a thought.



Forgot to add... When my first Mallory pump died, I did the same as you and tried swapping relays in the PDC, even went to DC and bought a new relay. Didn't help, but letting the truck sit awhile and then attempting a re-start gave me positive psi's ( just enough for a start-up), then the Mallory quit again.



Scott W.