78 K-10 Dual Tank Install

[David House]

When I bought my 1978 K-10 it only had the passenger side tank and the selector switch and selector valve are long gone. I want to install both tanks, the selector valve and the selector switch and put it back to stock as much as possible. Can anyone point me to the wire and plumbing diagrams so I can recreate a working system? Thanks

 

[Dave M]

Here's the way l did mine, l had to start from scratch and used a dedicated pump for each tank.

https://www.gmsquarebody.com/threads/fitting-of-twin-gas-tanks.28968/page-2

 

[75gmck25]

If you have a three port fuel pump with a return line, the hard part of a near stock conversion is to find the old-style 6 port tank solenoid (no longer sold new) that only requires a single powered wire to switch. I’m not sure if the ‘78 used the newer 6 port solenoid that has a multi wire connection, or the old single wire switch.

Bruce

 

[AuroraGirl]

my stock 1980 has this kind, no idea what it is. in a bucket somewhere, i saw one that came out of a 79 or 78 best i can tell. It matched. But it may not have been original or retrofitted or from a different truck. i say 78 because i have the fuel tanks for a 78 k10 and the switch for that truck was in the same bucket as the valve. i cant imagine they are good anymore(the valves) but hopefully it helps

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[AKguy]

The folks at EFI System Pro can hook you up.

 

[C10MixMaster]

1977 wiring

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1979?- 1986

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1987 with intank pumps

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[78C10BigTen]

If you have a three port fuel pump with a return line, the hard part of a near stock conversion is to find the old-style 6 port tank solenoid (no longer sold new) that only requires a single powered wire to switch. I’m not sure if the ‘78 used the newer 6 port solenoid that has a multi wire connection, or the old single wire switch.

Bruce

78 was 3 port single wire. Mine is....

 

[eskimomann209]

@gmachinz makes a whole plug n play wiring kit. Comes with the selector valve and dash switch. You gotta run the plumbing for the fuel lines tho.

 

[David House]

Thanks for all the input, I appreciate it, I'm going to try and plumb/wire it back to a stock setup as much as possible. If I were keeping the truck I would probably go with the two electric pump system though.

 

[taggtwo]

Jabin, has had my power window harness for about three months now. He must be busy. I sure would like to have it back!!

 

[Dan _79]

If you have a three port fuel pump with a return line, the hard part of a near stock conversion is to find the old-style 6 port tank solenoid (no longer sold new) that only requires a single powered wire to switch. I’m not sure if the ‘78 used the newer 6 port solenoid that has a multi wire connection, or the old single wire switch.

Bruce

Hey Bruce, I realize this message is 4 years later. I'm wrestling with the exact situation you described above and I'm wondering if you have any advice. I have a 1979 K10 with dual tanks. The selector valve or solenoid is broken (cracked) and needs to be replaced. Until reading your post I was searching for a new solenoid to replace the broken one.

 

[Dleslie212]

I had the same thing happen with my 77 K10 a few years back. I was replacing the fule hoses, and I snapped the barbed end off the selector valve. I ended up replacing with the newer version and rewiring the valve.

 

[Dan _79]

Thanks @Deleslie,

A few questions:

Did you rewire it with a six pin wiring connection?
Does your truck have three port sending units or something different.

Much appreciated -

 

[Dleslie212]

Thanks @Deleslie,

A few questions:

Did you rewire it with a six pin wiring connection?
Does your truck have three port sending units or something different.

Much appreciated -

It had the old three port valve, with single power wire.

I replaced it with the newer six port version, and when you do that, you have to completely rewire the valve and selector switch. I believe it has six wires instead of 1, if I remember correctly. There are a ton of threads on here about wiring and replacing, threads that I used when I was replacing mine

My sending units are three port. One feed, one return and one vent each

 

[chevy1979_RAI]

Hey Bruce, I realize this message is 4 years later. I'm wrestling with the exact situation you described above and I'm wondering if you have any advice. I have a 1979 K10 with dual tanks. The selector valve or solenoid is broken (cracked) and needs to be replaced. Until reading your post I was searching for a new solenoid to replace the broken one.

Single wire 6 port fuel selector valve - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Single wire 6 port fuel selector valve The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

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