low voltage at fuel pump connector, possible CCRM? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

mr.three-ford · 01-01-2011, 19:24

hi folks. i have a '96 mustang gt. it began running rough, then got progressively worse over a few weeks. then i couldn't start it. i checked for fuel at the valve on the rail, ign on, eng off. i got no fuel at all. while having engine cranked, i re-checked and got some fuel, but not much. it burbbled out rather than squirting. i have changed the filter. the fuel that drained out was nasty yellow, but the filter wasn't the cause. i checked the brown/pink (looks purple to me) and black wires at the fuel pump connector behind the tank. I only measured 7vdc. i ran a wire (cat-v,lol) from the battery to the female pins that lined up with the br/pink and black wires. the fuel pump then began to work, flowing gas thru the line i had in place to the gas can. is this too obvious? if i have 7 volts at the connector, and the pump opperates when given a true 12 volts, it has to be the CCRM, right? does anyone know the pin-out of the CCRM itself? i suppose that if i read the voltage at the module itself, i'll know for sure if that's my problem.

**Bert** · 01-01-2011, 20:21

What engine is it?

mr.three-ford · 01-02-2011, 08:33

it's a '96 gt, 4.6 sohc.

mr.three-ford · 01-02-2011, 08:39

And why can't i find any referrence to the CCRM when searching auto parts websites? I have followed a few threads here which referred to the CCRM (constant controll relay module) as the component that supplied the power to the fuel pump. does anyone have any knowledge of this part?

**Bert** · 01-02-2011, 09:12

Here's the diagram for the pump circuit.

mr.three-ford · 01-02-2011, 17:08

thank you, bert. that's very helpful. i can see that i'll need to trace that low voltage back through a few components. i'll start by making sure that the ground is good at that black wire. could someone clarify for me, i should have pressure on the fuel rail when the ignition is on, but the engine not started, right?

**Bert** · 01-02-2011, 20:03

The pressure builds when the key is turned to run. The pump will run for a few seconds and quit until the engine is started. The pressure will gradually drop after the car sets for awhile. That's why the pump runs the short time when the key is turned to on. You won't have 12v at the pump all the time the key is on unless the engine is running or you bypass the ccrm.