No power to fuel pump relay

QUAKER_71

MEMBER
1997 FORD EXPLORER
178,000 MILES

Trucks been sitting in the garage for a few months and has not been cranked. Battery was dead so I replaced it. It turns over good but will not start. Will start if you feed fuel into the intake. Cannot hear the fuel pump come on.
Checked the fuse to the pump it checked good but swapped it out anyway. Swapped the relay out with the one for the PCM. Both work on the PCM but not the pump. Checked the roll over kill switch in the passenger floor board. It was not tripped that I could tell. Jumpered out the switch plug to make sure and still no power to the relay. Other than chasing down the wiring not sure what else to check?

1 Reply

CJ MEDEVAC

MECHANIC
11,004 POSTS

JUST SOME DUMB QUESTIONS FROM A JEEP GUY TO GET THINGS STARTED. MAYBE OTHERS WILL JUMP IN. AND THEY DO, MOST OF THE TIME!

A RELAY IS A SWITCH CONTROLLED FROM ANOTHER LOCATION--LIKE A SOLENOID----POWER ACTIVATES AN ELECTROMAGNET AND "MAKES" THE SWITCH

EVEN IF THERE IS NO ACTIVATION SIGNAL (VOLTAGE)---THERE STILL MAY BE VOLTAGE TO THE CONTACT PART (SITTING IDLE, WAITING TO MATE WITH THE OTHER CONTACT)

JUST TO SEE WHAT AIN'T WORKING (MAYBE), I HAVE TAKEN THE TOPS OFF OF RELAYS (CAREFULLY) AND "F. INGERED" THE THE CONTACTS TOGETHER MANUALLY, AND LISTENING FOR THE PUMPOR YOU COULD CHECK WITH A VOLTMETER OR YOU CAN "JUMPER" WITH THE RELAY REMOVED.I LIKE THE TOP REMOVAL METHOD MAINLY BECAUSE THERE IS NO CHANCE OF JUMPING THE WRONG PINS AND FRYING SOMETHING, IT'S SORTA FAST TOO. THIS MIGHT NARROW DOWN TRACING WIRES IF IT GOT THAT FAR

I CAN POSSIBLY GET YOU SOME DIAGRAMS, WIRING, AND MAYBE COMPONENT LOCATIONS. BUT I NEED MORE ABOUT YOUR RIG---EXACT NOMENCLATURE AND ENGINE SIZE AND TYPE, 2WD OR 4WD. ANYTHING ELSE

MITCHELL I IS PICKY ON WHAT YOU FEED IT TO SEARCH

IS IT POSSIBLE THE FUEL PUMP SEIZED UP?

IF ABLE OR YOU WANNA WAIT FOR DIAGRAMS--YOU MIGHT MOMENTARILY "HOT WIRE" THE FUEL PUMP NEAR THE TANK---AND SEE IF IT WILL RUN FOR A FEW SECONDS RIGHT OFF OF THE BATTERY. BEFORE YOU GO WILD

JUST FOR GIGGLES, MAYBE A GOOD SMACK ON THE FUEL TANK.I'VE SEEN IT WORK A FEW TIMES

I'LL TRY TO HELP--I'LL BE OUT OF POCKET TOMORROW AFTERNOON

THE MEDIC