Dual tanks, advice from the savvy
 

How to use both tanks again, ex-mechanic did something to the switch, (electrical) it gets no power. No noise when switching. Bolt in cut-down hose on switching valve, is it possible that mechanic installed switch valve wrong? Because it didn't work right, as it would shut off. This is why he switched to one tank. Brand new switching valve.

Everything worked fine when I bought the truck, all this bs just wanting gas gauge to work, it acted more like a clock. And still doesn't work. I'm tired of wasting gas due to overflow from tank.

Any advice or experience on what to do, I want to use both tanks again.
How far does switch button wires run, and where are they supposed to go (connect to)

As always many thanks for your help. It is most sincerely appreciated.
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Re: Dual tanks, advice from the savvy
 

What year is your truck? There are two different systems between 73 & 91.

Re: Dual tanks, advice from the savvy
 

the easy way to tell witch switch you need is if your truck is a TBI truck or not the TBI switch also powers up the fuel pump

Re: Dual tanks, advice from the savvy
 

84 swb
305 cid
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Re: Dual tanks, advice from the savvy
 

From the 1984 GM manual....
Seems the editor that day was napping as both tanks were labeled "left tank". Best verify tanks by wire color....

Re: Dual tanks, advice from the savvy
 

The switch and selector valve are the same. The TBI tank wiring harness is different to feed power to the pumps.

Re: Dual tanks, advice from the savvy
 

I attached the Dual Tank Parts Book Illustration pages and the NL2 Dual Tank wiring schematic.
Hopefully these will help you sort out what's wrong.

Re: Dual tanks, advice from the savvy
 

Thanks for posting those hatzie, I'll be doing the "get my dual tank to work" thing soon.