Me again

[jrh55]

I'm calling on the wise friendly folks here again, can anyone explain how the saddle tanks are supposed to work? I'm so old all I remember of them is we used to have a brass switch, turn the switch change the tank. Now I have a fuel pump on the engine and it seems multiple solenoid type switches.

as always my thanks for everyones kindness

[wyattglock]

There is a pollak valve under the truck on the passenger side just in front of the tank. A switch in the dash controls which tank you are pulling from and which sending unit is showing on the gas gauge. Depending on the year of your truck there are 2 different styles of switching valves and dash switches. There is a 3 port for carb applications, and a 6 port for fuel injected applications. The dash switches are momentary, or 3 position, for carb trucks. For fuel injected trucks the switch is 2 position switch that indicates the tank being used by switch position. Either setup sends the signal from the sending units to the fuel gauge on 1 wire, the level just changes on the needle.
If anyone else has any corrections to what I have put on here, thanks in advance. This is as good a description as I can give right now, hope it helps.