Dual fuel tank issue.
05-03-2018, 05:48 PM
#1
Senior Member
Thread Starter
Dual fuel tank issue.
My ‘89 f150 has the dual tanks and no matter what I have the switch set to, it only draws from the rear tank.
If I set it to the front tank, it will show the fuel level of the front tank, but it draws fuel from the rear one. The problem has been going on for about a year. The dual function reservoir (or fuel selector valve is that’s what you wanna call it.) has been replaced since then, but has changed nothing. Both of the low pressure fuel pumps were replaced about 2-3 years ago, the high pressure one was replaced last year.
I am being led to think that it could be an electrical problem in the switch or something. But I can’t find anywhere to get a new one. The switch on the dash has 6 connections on the back of it, but all of the ones I see online have either 2 or 4. So I’m just wondering if anyone here could have an idea of what exactly is causing the problem.
If I set it to the front tank, it will show the fuel level of the front tank, but it draws fuel from the rear one. The problem has been going on for about a year. The dual function reservoir (or fuel selector valve is that’s what you wanna call it.) has been replaced since then, but has changed nothing. Both of the low pressure fuel pumps were replaced about 2-3 years ago, the high pressure one was replaced last year.
I am being led to think that it could be an electrical problem in the switch or something. But I can’t find anywhere to get a new one. The switch on the dash has 6 connections on the back of it, but all of the ones I see online have either 2 or 4. So I’m just wondering if anyone here could have an idea of what exactly is causing the problem.
05-03-2018, 08:31 PM
#2
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Location: Memphis, TN, Earth, Milky Way
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Changing parts is not diagnosis, or repair (as you're seeing). It just wastes time & money. To test a pump, apply 12V to it. If it runs & makes its target pressure, there's no reason to replace it. Always test any replacement part the same way you tested the old part - if it fails, either you're testing them wrong, or you bought a bad one. What are the brand, PN, & source for each part you've replaced?
This shows the wiring:
(phone app link)
Where exactly have you checked for the switch already? I'm guessing this is it:
If it is, use that PN to shop eBay, RockAuto, etc. But don't buy a new one unless the old one fails the diagnosis.
This shows the wiring:
(phone app link)
Where exactly have you checked for the switch already? I'm guessing this is it:
If it is, use that PN to shop eBay, RockAuto, etc. But don't buy a new one unless the old one fails the diagnosis.
