tank selector switch problems

[79HIGHSIERRA]

hey guys i have an issue with my tank selector switch the gauge reads a full tank but i cant hear the tanks turning on when i hit the selector switch and idk which tank the truck is on im thinking id be better to just rewire the whole switch and tanks but idk where to begin any help would be greatly appreciated thanks

[Captkaos]

What do you mean "hear the tanks turn on"?
If it is anything but an 87 with EFI, you won't hear anything unless you are under the truck, it is just a switching valve changing the source of the fuel from one side to the other.

[79HIGHSIERRA]

oh well i owned an 81 scottsdale without EFI and when u switched the tanks tanks i heard a noise like the valve opening or something idk but anyways how do i fix this problem of the switch not working and everything

[jason d o]

I know what you mean. My switching valve works all the time but when i switch from one tank ill hear a buzzing noise when it switches over but if i switch it back to the other tank i wont hear the buzzing noise, but it switches over anyway.

[79HIGHSIERRA]

thats exactly what im talking about thanks jason have u ever had to fix the switch or anything like that my gauge reads full but i have no idea if its real cuz the truck was sitting for 5 years before i bought it so if u can help me thatd be awesome

[jason d o]

Never had to fix it yet. One thing it does sometimes is when i switch over to the other tank itll go way past full. what i have to do then is switch back to the other tank and then back again to get it to register correctly. It must be a ground problem.

[79HIGHSIERRA]

yea ive had that problem before on my 81 especially when i just filled the tank completely full but i just dont know where to begin with this dang switch lol and i dont wanna take it down to just one tank because the truck is on a 9 inch lift and 40s so it would be nice to have both tanks u know

[bake74]

     I would trace the power supply from your switch back to your valve and check both sides of the switch and valve, that way you could eliminate the switch and valve first.  Then move on to either the sending units or your printed circuit board/gauge.

[79HIGHSIERRA]

well thank you i will try that and keep you posted on the result much appreciated 

[Captkaos]

There is a tech article I posted on fixing a switch with bad connections.