whats up. well i just installed a autometer tach on my friends car (civic hatch) cuz he doesnt have an rpm gauge in his car. on the tach theres no wires for a light source. only power ground and rpm signal. how does the thing light up at night? is there a sensor that auotmatically puts the light on when it gets dark or does the light stay on all the time? (havent got a chance to start the car yet to check cuz his msd blaster coil is shot)

 

a friend of mine has some aftermarket tach on his tacoma, and the light just stays on the whole time.