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Old 06-19-2012, 06:37 PM   #1
gchemist
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1978 1/2 ton dual tank indash switch question

Trying to help out an owner. Can someone help with the correct 78 switch wires and connections? I've tried all my sources with diagrams and no luck. Can someone that owns a 78 pull the switch and take pic or look?

Howdy, my 79 year old buddy forgot how the wires go into his new switch he bought. there are 5 wires: pink/black, tan/white, green, blue, brown.
on the back of the switch there are 2 posts on one side and 3 posts on the other. what colors go to what posts?
Thank you, sure appreciate your time!

hellonwheels1957@hotmail.com
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Old 06-19-2012, 11:22 PM   #2
ray_mcavoy
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Re: 1978 1/2 ton dual tank indash switch question

I don't have a 78, but from the wire colors you posted, it looks to be the same as 77.

And for 77, the wire arrangement on the back of the switch is:

The pink/black & light green wires both go to the side with 2 terminals. The pink/black wire goes to what would be the "center" terminal if there were a 3rd on on this side.

The tan (brown) wire goes to the center terminal on the side with 3 terminals.
The blue wire goes to one of the outer terminals on the side with 3 terminals. It's the one directly across from the light green wire.
The tan/white wire goes to the other outer terminal on the side with 3 terminals. It's the one directly across from the "empty" spot on the 2-terminal side.

And just to make sure things are hooked up okay on the other end, the other end of the pink/black wire should lead to an "IGN FUSED" slot on the fusebox. The other 4 wires should go through a plug on the firewall and run back to the fuel tank area where the light green one hooks to the solenoid valve. The tan (brown) wire plugs into the tan wire that is running down along the passenger side frame rail and would have gone directly to the tank on a single tank truck. The tan/white wire goes to the pass side sending unit and the blue wire goes to the driver side sending unit.
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Old 06-20-2012, 10:24 AM   #3
gchemist
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Re: 1978 1/2 ton dual tank indash switch question

THANKS FOR THE REPLY!!
I've forwarded your info to the person that posted the question. I sent you a PM with info and credit.
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