Author Topic: 1987 R20 Dual Tank wiring  (Read 8185 times)

Offline zieg85

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    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: 1987 R20 Dual Tank wiring
« Reply #15 on: April 29, 2020, 10:58:16 AM »
I just looked at the wiring again above.  Should the tan 920 and tan/white 120 be connected since the switch is no longer in play?

Yes.  And for the gauge, pink 30 should connect to pink/white 930.

Thanks Rich, I will report back with the results
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction

Offline David Staines

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Re: 1987 R20 Dual Tank wiring
« Reply #16 on: June 10, 2023, 08:54:40 PM »
I have been dinking around with putting a holly sniper on my originally TBI dual tank that was later converted to carb. I've been searching all over for some information on the fuel pump power and tank switch configuration with little luck... even searching on these forums. I finally found a good reference schematic that made sense in this thread ( @zeig85 ). I undid all of the splicing done to bypass the tank selector switch and installed a T setup with check valves to bypass the tank select solenoid (doesn't take 65psi well) and found I only needed to route my fuel pump power from the holly setup to the brown and white input of my tank switch... which is in the engine bay anyways. It is amazing what finding the right schematic will do. Thanks for archives and allowing me to deliberately bump this VERY useful thread.

Offline VileZambonie

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