The gas guage on my 69 hasn't worked since I bought it, and I'm trying to fix it.. I put in a new sending unit, and it's grounded. Everything's hooked up but when I looked at the harness comming off the back of the guage there was a cut wire comming out of the middle plug? I'm assuming that's a ground because the guage is past full. Any ideas?

There should be two wires attached to the gauge. Pink, gauge power, and tan, to tank sender. The middle post should be grounded to the metal back of the cluster.

Thanks for the help.