Question regarding dual tanks

[1974ChevyC10]

the truck i bought recently someone along the way put an extra gas tank in it but for some reason didnt put a switch to select between the two tanks.everything else appears to be there for the dual tanks just no switch to go between the two tanks.how hard is it to wire up a switch and can i just buy a gm style selector switch and use that or do i have to get some other kind of switch and if so what kind.

[FLEET72]

If you are not finding a switch it could be that you have a manual valve. Follow the fuel lines from tank to pump and look for a fuel selector valve. Here are a couple examples of manual valves, without return on left with return on right.


An electric one could look like either of these two, the left is a simple selector with no return, the right one has return.

[1974ChevyC10]

fleet72-that could be only reason i havent really crawled underneath ol red yet is because i had pretty major surgery just about 2 months ago so crawling under stuff still is kinda difficult for me.if it does have a manual switch ill relocate the switch to somewhere easier accesible or if possible change it all over to electric.i would prefer the electric switch so i can go between tanks on the fly.

[FLEET72]

Originally Posted by 1974ChevyC10

fleet72-that could be only reason i havent really crawled underneath ol red yet is because i had pretty major surgery just about 2 months ago so crawling under stuff still is kinda difficult for me.if it does have a manual switch ill relocate the switch to somewhere easier accesible or if possible change it all over to electric.i would prefer the electric switch so i can go between tanks on the fly.

Didn't realize, sorry. Another way would be to look for the valve handle on the floor of the cab, usually accessible from the drivers seat. On my '60 it was on the left side of the hump just under the front edge of the bench seat.

[1974ChevyC10]

Originally Posted by FLEET72

Didn't realize, sorry. Another way would be to look for the valve handle on the floor of the cab, usually accessible from the drivers seat. On my '60 it was on the left side of the hump just under the front edge of the bench seat.

its cool you didnt know i had surgery.there is a switch in the cab of the truck on the dash underneath and to the left of the steering column which im not sure what its for.could be for the tanks who knows.ill check what you suggested and when we get around to the engine swap ill have my dad crawl under there and look since he is going to help me with this.

[Gregs71]

My dad put a manual switch on the floor board at the base of the seat near the hump on the passenger side. Sometimes as a kid, I would accidentally switch it and the truck would die (because the tank was empty).