Gas Gauge past full

[benzesrule]

Hi, I have a 84 K10 with dual tanks and the gas gauge is past full at the 3 oclock position( right tank) and on the full mark on the left tank. I found a broken ground wire behind the gauge cluster and fixed it.  I even ran a new wire replacing the pink wire from the selector valve to the cluster and the gauge stayed the same. I replaced the fuel gauge with one that I had laying around, stayed the same. I noticed someone has replaced the left tank and it is a 20 gallon while the right tank is a 16 gallon. I use the right tank most of the time. This truck had 16 gallon tanks from the factory. The selector valve is operable. Both tanks are grounded. Any suggestions?

[zieg85]

A dirty switch will cause that problem, been there.... Just fixed my switch on my 85 last night, did that same thing..

[87454westernhauler]

A dirty switch will cause that problem, been there.... Just fixed my switch on my 85 last night, did that same thing..

My 87 had a very similar problem with the switch.

[benzesrule]

It has a brand new switch for the fuel selector.

[1979C20]

Kind of related, how in gods name do you remove the switch from the dash?

[DnStClr]

Twist the switch gently to the left and right. It should come loose. Then wiggle it up and down as you remove it. Don't get too gorilla- like with it. Some finesse is needed..