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1975 K20 Duel Tanks…..problem

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Buckshot0351

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The fuel situation on this truck was F’d when i bought it. I replaced both tanks and sending units as well as the switch on the dash and the Fuel Tank Silenoid to switch between tanks. I think my silenoid is the problem. I replaced it with one from Amazon. It is a generic 3 port single pole just like but not as robust as the original. The original is not made anymore so this seems to be my only option. However, with everything replaced it is still only drawing from one tank, the default passenger side tank. I am getting power to the single pole silenoid via light tester and is at a steady 11.85 volts. I can hear a small click from the silenoid when it gets juice. I have it mounted up right and the ground is good. The dang thing just won’t draw from the other tank. What am i missing?

The method of testing was 2 glass jars with fuel in them and fuel line from each jar to each intake port on the silenoid at the same time and ran the truck flipping the switch. It stays drawing from the same jar.

My best guess is that i got a bunk silenoid?
 
No, its not. And this is the problem im running into. Those newer good ones are 5 pin pigtail which if i were to switch over to from my current single wire, would be waaay to much extra shit and id probably plumb a manual valve in somewhere. Its been almost a year since i started this fuel system endeavor and last night i checked again on amazon and found a single pole 6 port that wasnt there when i started this. I got it ordered and will try it. Seems to be the same cheap Chineseium product as the one i just tried. Fingers crossed.
 
I can’t be the only one who has ran into this so i figured id see what the more experienced folks have done.
 
FWJ, Thank you for taking the time to post links. I think those 3 ports are the exact one i used from amazon.
Im wondering if maybe its not grounded enough. Maybe its grounded just enough to start initiation but not grounded enough to complete the full 12v. Or is that not how it works?
 
Buckshot0351 said:
FWJ, Thank you for taking the time to post links. I think those 3 ports are the exact one i used from amazon.
Im wondering if maybe its not grounded enough. Maybe its grounded just enough to start initiation but not grounded enough to complete the full 12v. Or is that not how it works?
Click to expand...
Make sure you ground it good and you can also load test it and see if you are getting full 12.5 volts.
And I am assuming you're hooking up the hoses the right way.
You should have 2 in one out.
I don't remember if they are clearly marked
 
Buckshot0351 said:
FWJ, Thank you for taking the time to post links. I think those 3 ports are the exact one i used from amazon.
Im wondering if maybe its not grounded enough. Maybe its grounded just enough to start initiation but not grounded enough to complete the full 12v. Or is that not how it works?
Click to expand...

you are welcome; I wish I could be more helpful.
 
Update: Got the single pole, 3 port one working. I received the more proper single pole, 6 port from amazon and tested it directly from the battery and it seemed to work really strong. So i used a jumper wire as a really good ground on the 3 port that i was trying to get to work and it works now. Nice and strong. Just needed a better ground.
 
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