voltage meter-how does it hook up
 

I have a VDO voltage meter in my 86 911. About 6 months ago, it stopped working and I dont have a clue why. I could swear that it had 2 wires going to it, but now I can find only one. There is a positive and negitive post on the back and a black wire going to it, which I assume is the negitive. When I trace the black wire, it connects to a screw on the dash. The white wire goes over to near the steering wheel and then it does not attach to anything. Does anyone know how these are supposed to hook up? Thanks for any reply.

Hook up the white "hot" wire to any switched hot lead, like the one going to your radio.