dual gas tank issue

[infamouschevy]

i have two as tanks on my truck but only the driver side 1 works i wana know what i could check 1st or where to start checking when i bought the gguy told me that it didnt work.

[Cowman85]

i would start at the switch in your cab, then work back to the rear end switch.
Do you here the switch activate when you change tanks?

[Captkaos]

What year truck?  I would have someone flip the switch and listen to the valve.

[infamouschevy]

its an 85 Ive never actually tried to use it when i bought the guy just told me it didn't work but ill try those things first and see what happens. thanks

[bake315]

its an 85 Ive never actually tried to use it when i bought the guy just told me it didn't work but ill try those things first and see what happens. thanks

Years ago we had an 85 3/4 ton with dual tanks.  It had a bad habit of blowing the fuse every time you tried switching the tanks.  I think it ended up being a short in the switching valve.

[velojym]

My '86 had me wondering for a bit, as flipping the switch didn't show any change on the gauge,
and the truck didn't die either. Hmm...
When I was poking around to find the source of a tranny fluid leak, it became obvious that my pre-purchase wasn't as thorough as it ought to have been...
The left tank was gone. Hoses and wires had been cut and the tank removed at some point.

I'm debating on whether to replace it (probably) or mount a Blazer tank and engineer an under-bed tool compartment for the empty tank area. I'd leave the right tank in place either way.