fuel gauge

Every time I turn on the on the headlights or parking lights in my 68 convert I get them but I also loose my fuel gauge. If im at a full tank it will drop to around half and anything below that will drop the needle to past empty. Its a standard dash with no other gauges but the speedo. thanks

I wasn't sure where to post this, but seeing as it might be in the wiring, I'll ask this question here. So, my '67, as well as my brother's '68 have non-working fuel gauges. Mine was previously in beside the speedo, but it never worked (at least since I remember) and I put console gauges in. I...

I ordered a new Spectra Premium Industries sending unit. I would like to test it before installing. Here is what i am thinking: - Ground the sending unit - Hook the sending unit up to the gas gauge - Power and ground to the gas gauge - Lift the arm of the sending unit Should that work...