I have a 2000 f350, 6 speed trans that has had intermittent fuel issues and now the problem seems to be almost all the time now. ALL fuses are good, all relays that i can find are good. However, there's only 6-7 vdc at the pump. Ground at the pump is GOOD when ohmed to negative battery terminal and measured 13.5 vdc harness ground to battery positive. I have searched hi and low for the fuel pump relay. Prodemand says its in teh fuse block on drivers side fender, it is not. Internet search says its in the dash below and to the left of the radio, it is not. Is this pump controlled strictly by the PCM? One thing i have noticed is that as long as the key is on, there is voltage at the pump power. It never times out and cuts power off like every other superduty 7.3 does. Does anyone know if i can swap in a spare auto PCM just to see if it runs the pump correctly? any help is appreciated.
fuel pressure/ pump issues
- Thread starter Short Bus
- Start date
bruce
Active member
The relay should be right there with the blinker relay, behind the radio. It's fairly easy to swing in a pcm. It's worth a shot. If you go from positive battery terminal to positive on the pump whay do you get? Should be 0 vdc, if its higher then you have a voltage drop somewhere.
Arisley
Moderator
That's an E99 PCM, should work.
Scratch previous post, I forgot to put relays back in. Apparently the one in dash is in fact the fuel pump relay. All is good now. Key on and I have good voltage for 20 seconds then it drops back down to 7 vdc. Cycle key back off and then on, volts go back to 13 for 20 seconds. Looks like we have a bad pcm
