Do guages care?

["Frank Bakanau" <FBAKANAU@xxxx>]

I'm trying to figure out my weird gauge problem. My c300 was rewired to 12
volts. The gas and temp gauges only work if the door is closed (interior
lights off) and the map light is on. Open either door and the gauges go
dead. Everyone I've talked to says its a ground problem. To make a long
story short, I'm thinking of taking the "gauge power" wire and going right
to the ignition switch, rather than trying to figure out the rats nest of
wires. Do the gas and temp gauges care if its 12 volts? I have no idea at
this point if they are getting 12 volts when they do work. I still do not
have a manual (one is coming) but it may not be that helpful since the car
is re-wired.