I got my VDO Electric oil pressure gauge and EGT gauge today. The back of the oil pressure gauge has connections for + and - for the light, + and - minus for the gauge, and one for the signal wire. Similarly, the EGT has connections for + and - for the light, + and - minus for the gauge, and two for the signal wires.

My question is, what does the guage need power for, besides the lights? Why does it have seperate power and ground on the gauge itself, besides the light?

Rob

Since they are electric you need power to the motor and sensor pickups.