Why are the fuel pumps running with the key off and out of the switch

Tiny
DIXON1
  • 1987 FORD F-150
  • 200,500 MILES

My truck has dual tanks and which ever tank is selected and the inline pump continue to run with the switch off also the relay buzzs while the key is off I am totally at a loss over this issue any help will be greatly appreciated

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Friday, May 4th, 2012 AT 12:21 AM

30 Replies

Tiny
CJ MEDEVAC
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POSSIBLE FUEL PUMP RELAY'S CONTACTS ARE STUCK TOGETHER

SOMETIMES A GOOD THUMP WILL KNOCK 'EM LOOSE

IF SO, REPLACE IT ANYWAY---I'LL DO IT AGAIN

THE MEDIC

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Friday, May 4th, 2012 AT 12:27 AM
Tiny
DIXON1
  • MEMBER

Ok brand new relay, still same issue fuel pump running with the switch off. Changed with the battery disconnected to avoid shorting out the new relay.

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Friday, May 4th, 2012 AT 8:11 PM
Tiny
CJ MEDEVAC
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I NEED YOUR ENGINE SIZE

I "MIGHT" BE ABLE TO GET THE WIRING DIAGRAM(S) FOR THE FUEL SYSTEM

MANY TIMES A VEHICLE OF THAT AGE DOES NOT SHOW UP IN MITCHELL I

YOURS DOES---I WANNA INSURE I GET YOU THE CORRECT DIAGRAM, AND NOT CONFUSE YOU WITH 4 OR 5 THAT DOES NOT PERTAIN TO YOUR TRUCK

IMMA JEEP CJ KINDA GUY, I HAVE EXPERIENCE WITH MY DAD'S '86 THUNDERBIRD----IT HAD 2 FUEL RELAYS

MITCHELL USUALLY HAS LOCATIONS OF COMPONENTS LABELED BESIDE THE SYMBOLS ON THE DIAGRAM. EZ TO READ AND TO FIND STUFF

EVEN IF THERE IS NOT A 2ND RELAY, YOU WILL EZily SEE EVERY ELECTRICAL COMPONENT IN THE SYSTEM, AND MIGHT COME UP WITH "WHAT ELSE" COULD BE CAUSING THE VOLTAGE TO CONSTANTLY FEED THE PUMP

I WAS ON-LINE WHEN YOU RESPONDED, I MAY STILL BE ON IF YOU RESPOND SOONRIGHT NOW, MITCHELL I IS STILL PULLED UP WITH YOUR INITIAL INFO

YOUR TURN

THE MEDIC

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Friday, May 4th, 2012 AT 8:32 PM
Tiny
DIXON1
  • MEMBER

Sorry cant believe I left that out 302 efi

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Saturday, May 5th, 2012 AT 1:32 AM
Tiny
ASEMASTER6371
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The pcm grounds the fuel pump relay. If you remove the relay, do the pumps turn off?

Roy

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Saturday, May 5th, 2012 AT 1:40 AM
Tiny
CJ MEDEVAC
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I JUST GOT BACK IN FROM A FUNERAL KINDA CHOW DEAL THINGEE FOR A FRIEND OF MY FAMILY

I'M ABOUT TO SEARCH FOR YOUR INFO

THE SITE OUTTA "PROMPT" ALL THAT KINDA INFO FROM YOU WHEN YOUR QUESTION IS SUBMITTED. SO FAR, THEY HAVEN'T INCORPORATED IT IN. THINGS LIKE "LX"--"LTD"--"SE" SOMETIMES MAKES A DIFFERENCE WHEN YOU LOOK FOR INFO

I'LL BE BACK SOON AS I GET IT

THE MEDIC

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Saturday, May 5th, 2012 AT 1:40 AM
Tiny
CJ MEDEVAC
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2ND ATTEMPT TO SEND THIS

1-4) ENGINE COMPARTMENT

5) ENGINE COMPARTMENT AND UNDER DASH

6) UNDER DASH AND INSTRUMENTS

7) REAR COMPARTMENT AND ACCESSORIES

I'M SURE THESE WILL NOT BE CLEAR ON THIS SITE---I WILL SEND YOU A PRIVATE MESSAGE TO PRIVATELY OBTAIN YOUR EMAIL ADDRESSTHEY ARE VERY CLEAR IN MY DOWNLOADS

TO GET TO MESSAGES

AT TOP OF THIS PAGE CLICK YOUR USERNAME> PAGE COMES UP> LOOK LEFT---YOU WILL SEE MESSAGES. YOUR INFO IS NOT BROADCAST WORLD WIDE IN THERE

I CANNOT SEND ALL IN ONE SHOT ON THIS SITE (I JUST TRIED, LOST A NOVEL I WROTE YOU)---SO I WILL DO 2 POSTS

I CANNOT COPY CHARTS IN MITCHELL I---SO IF YOU NEED TO KNOW A COMPONENT LOCATION, TELL ME WHAT IT IS, I WILL SEARCH THE CHARTS AND PASS IT ON BACK TO YOU

IF YOUR TRUCK IS A KEEPER---YOU MIGHT WANNA DO LIKE I DID, WITH YOUR DIAGRAMS---MAKES IT SO EZ!

SEE JANUARY 4TH ON THIS POST---MY REPLY THAT STARTS OUT, "OK HERE'S THE DEAL"

MESSAGE SHOULD BE A MINUTE OR SO AFTER I POST THESE 2 POSTS

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Saturday, May 5th, 2012 AT 2:32 AM
Tiny
CJ MEDEVAC
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567

THE MEDIC

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Saturday, May 5th, 2012 AT 2:34 AM
Tiny
CJ MEDEVAC
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I'M S.CREWIN' IT ALL UP!

I WROTE THIS PREVIOUSLY:

IF YOUR TRUCK IS A KEEPER---YOU MIGHT WANNA DO LIKE I DID, WITH YOUR DIAGRAMS---MAKES IT SO EZ!

SEE JANUARY 4TH ON THIS POST---MY REPLY THAT STARTS OUT, "OK HERE'S THE DEAL"

THIS IS THE LINK:

http://www.2carpros.com/questions/1977-jeep-cj5-ignition-trouble

THE MEDIC

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Saturday, May 5th, 2012 AT 2:41 AM
Tiny
ASEMASTER6371
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Nice job CJ

Roy

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Saturday, May 5th, 2012 AT 2:41 AM
Tiny
CJ MEDEVAC
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THANK YOU!

IF HE HAD A JEEP CJ---I'D HAVE HIM SQUARED AWAY BY NOW!

TOO BAD THAT'S NOT THEIR NEWER DIAGRAMS

I MAY NOT KNOW HIS RIG WELL---BUT I CAN SHOVEL HIM PLENTY OF INFO

I FELT SURE HE'D BE BACK BY NOW

HOWS YOUR EVENING GOING ASEMaster6371?

THE MEDIC

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Saturday, May 5th, 2012 AT 3:00 AM
Tiny
ASEMASTER6371
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Not bad, pal. Just trying to help out these people.

You have a good weekend

Roy

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Saturday, May 5th, 2012 AT 3:27 AM
Tiny
CJ MEDEVAC
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ME TOO

WIFEY SAYS I WRITE TOO MUCH STUFF

IF I WHACKED ALL THE WIRES OFF OF MY CJ RADIO, WOULD IT STILL RUN. THE RADIO. Lol!

THE MEDIC

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Saturday, May 5th, 2012 AT 3:34 AM
Tiny
DIXON1
  • MEMBER

Sorry for my lag storm and kids sport have me runnin in circles.
I will answer in order from my last post as best I can
1. Yes if I unplug the relay the pumps will stop but the relay buzzs upon reconnecting until I fully cycle the key
2. Ok sent my address

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Saturday, May 5th, 2012 AT 1:30 PM
Tiny
DIXON1
  • MEMBER

Ok went out and double checked if I unplug the brown and green pigtails from them 2 relays is the only way both pumps will shut down
there is a 3rd relay with a grey pigtail that has no effect on the pumps that I have noticed

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Saturday, May 5th, 2012 AT 3:07 PM
Tiny
CJ MEDEVAC
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ASEMaster6371----I THINK YOU NEED TO ANSWER THE "HANDS ON" STUFF

I'LL GET HIM THE DIAGRAMS WHEN I FINISH HERE

THE MEDIC

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Saturday, May 5th, 2012 AT 8:05 PM
Tiny
ASEMASTER6371
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Got you CJ.

When you pulled the fuel pump relay and the pumps stopped, this means the control side of the relay is staying engaged meaning it is grounded 100% of the time. This is what we have to fix.

Does this have dual tanks? If it does, disconnect the switching valve and connect the relay and make sure the pumps are off. You may have a wiring issue down at the switching valve.

Roy

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Saturday, May 5th, 2012 AT 8:29 PM
Tiny
DIXON1
  • MEMBER

My valve is original ford so there is no electric on the valve at all it works off of fuel pressure
i have an in dash switch that turns power on to either in tank pickup pump

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Saturday, May 5th, 2012 AT 9:37 PM
Tiny
ASEMASTER6371
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No, the switch operates a switching valve under the truck where the lines all meet. Take another look. If there is a switch on the dash, then there is electric under the truck.

Roy

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Saturday, May 5th, 2012 AT 9:42 PM
Tiny
DIXON1
  • MEMBER

Again this is an 87 all original. I had the valve out 3x already and there is no electrical on the valve what so ever
there are 2 springs within the valve that compress when the pickup pump pressurise against it

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Saturday, May 5th, 2012 AT 10:12 PM

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