fuel gauge 91 passat

My fuel gauge is acting up, when I fill the tank to to top, it only says half full on the gauge and sometimes the gauge dies completly and it show empty. Someone told me it might be a airlock, but i think the gauge is acting too funny for that to be the case.
Is my problem with the gauge behind the dash, or in the fuel tank ??

Or is it another probelm ? Don't really feel like dropping the fuel tank at all.

If you bank on top of the dash & it reads right it's the connector to the cluster. If not then it's probably the sender in the tank.

A lot of 90-93's had faulty solder behind the dash cluster.Mine did that for years, until I got so fed up and resoldered it myself. (how many times I looked in the rearview and side mirror to see If I was "dumping my payload" happened many a time ! :)

A tiny Radio Shack electronics wire solderer and fine wireflux works wonders. A clamping visual magnifyer helps too, if you are challenged in the eyes like me.Im nearsighted. Good Luck!

What did you actualy solder??? My fuel and temp guage used to work very intermittantly and have now stopped working all together. any info would be great!

I have the same problem on my 91 passat (fuel gauge is up and down, along with the water temp. so I would like to solder it to, but Idont't know what to solder?