STINGER SVMB Blue Volt Digital Voltage Meter Car Gauge

Easy to install, easy to adjust with a dmm....

The bright summer sun obscured my existing small red + - light that came on when the alternator failed, thus allowing the battery to fail and the engine to quit. The Blue Stinger is bright and easily visible, even in direct sunlight. And it looks nice installed below the ashtray area, where it provides a constant monitor of system voltage or battery voltage. The wires are only about 18 inches long. You must extend the wires and add two fuses. Black-----Connect to car metal body or ground. Blue ------Connect to ignition or accessory point in a fusebox, adding an inline 1A fuse. Blue is to turn on the display and activate the unit. Red------Connect to battery positive or as close as possible through a separate 1A fuse to read the alternator output at the battery. The red lead is the voltage that is monitored. The blue and red lead can be tied together through a single fuse about 1A and connected to an ignition at a fusebox. The ignition lead voltage would vary downward typically .4V as lights and blower fans are activated but still provides good monitoring of the charging system. There is an adjustment pot for calibration of the voltage reading against a DVM but the display brightness is not adjustable. I only have it a few days but hope it lasts a while.