Dual Tanks?
Thread Starter
|
New User
Joined: Dec 2005
Posts: 6
Likes: 0
Dual Tanks?
Am new member this is my first post appreciate any help. have had other Ford trucks with duals tanks but never any problems now have a problem switching tanks. Can anyone tell me how the switch under the dash works when switching from one tank to the other? Also there is a black cannister with 4 lines comming out of if just behind the pump and filter what is its function. Truck is 1989 F150 300 6 auto. Thanks
FTE Leadership Emeritus
Joined: Jan 2003
Posts: 161,999
Likes: 75
From: 3rd Rock
...Welcome to Ford Truck Enthusiasts!
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!
Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!
Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.
Lead Driver
Joined: Nov 2002
Posts: 9,555
Likes: 40
From: Concord, NC
The dash switch selects which in-tank fuel pump gets power. The black canister with the 6 lines going in and out of it is the selector valve, which is operated on pressure from the in-tank pumps. If one of the tank pumps fails, it won't switch tanks. Have a listen to see if each of the in-tank pumps are working.
Fleet Owner
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by dirtyneck
Am new member this is my first post appreciate any help. have had other Ford trucks with duals tanks but never any problems now have a problem switching tanks. Can anyone tell me how the switch under the dash works when switching from one tank to the other? Also there is a black cannister with 4 lines comming out of if just behind the pump and filter what is its function. Truck is 1989 F150 300 6 auto. Thanks
Note that the Fuel Pump Relay is grounded inside the EEC Computer.
Last edited by subford; Dec 4, 2005 at 08:17 AM.
Fleet Owner
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by dirtyneck
Am getting no power to either tank. Can someone tell me where 20 amp/guage fusible link is located? Thanks.
Trending Topics
Thread Starter
|
New User
Joined: Dec 2005
Posts: 6
Likes: 0
Thanks for the help subford will check it out. meanwhile have hotwired dual tank switch to get power to rear tank with key on and am back on the road. Not correct but functional until I track down real problem, thanks again, Jim
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Lead Driver
Joined: Nov 2002
Posts: 9,555
Likes: 40
From: Concord, NC
Can you hear if the frame mounted high pressure pump is working? I don't think the truck would run off of just the in-tank pumps though, so maybe it is working. If the high pressure pump isn't working, then check the inertia cut-off switch. It could also be the fuel pump relay. Listen for that to click when the key is turned to "run" and then click off after a couple seconds.
Thread Starter
|
New User
Joined: Dec 2005
Posts: 6
Likes: 0
Thanks EPNCSU yes the frame mounted pump works and the rear in tank pump works when hot wired thru the dual tank under dask swith. I think I got a bad front in tank pump and a bad relay. Can you tell me where pump relay is located? Thanks, Jim
Post Fiend
Joined: Mar 2002
Posts: 19,402
Likes: 38
From: Bonita Springs FL
The intank pump on a 1989 is not really needed. If it fails, the truck will still run. It's basically there to prime the high pressure pump if you run the tank dry. But I guess it could "help" the other pump out if it's weak/dying. Have you checked fuel pressure at the rail?
Lead Driver
Joined: Nov 2002
Posts: 9,555
Likes: 40
From: Concord, NC
The in-tank pumps are needed to operate the tank switching valve, and to supply the high pressure pump with fuel. The electric fuel pumps push fuel fine, but are not as good at sucking fuel. That's why there is a lift pump in each tank to get fuel to the high pressure pump.
