ok, i have my gauges hidden in the glove compartment and i just noticed that when i turn of the car/engine, the gauge still remains on. Will this discharge the battery?? Is it supposed to be like this??...I got the black wire connected on ground, and the red on power. The other 2 wires left are optional, right?? or do i have to connect them also??

 

connect the red power wire to another power source, like the illumination wire on the back of your HU.

The other 2 wires are optional, 5v, and a serial.

 

thanks, ill see if i can do that tomorrow.

 

or just fuse tap it with a mini fuse tap. they cost like 6 bucks at autozone. most of those fuse ports down there are switchable so its on/off. other gauges however have to find the switchable with illumination. some like my oil pressure gauge uses both, so i had to tap just on/off for the sender, and then illumination on/off for the lighting. i hope this makes sense.