dual fuel tank switch

[Kidduey]

I have an 81 k20 with a 350. Irecently replaced the sending unit on the drivers side tank along with the switch on the dash however I cant switch tanks from the drivers side to passenger side. What should I be looking for to correct this problem .

 

[SquareRoot]

Probably a bad switching valve, especially if it hasn't been used in a long time.

 

[JeffK10America]

What he said … you should hear a click when it switches. I know mine does .. especially since I replaced all of it..