MAN# 650092:BHLY-3051 ROUND VOLTMETER GAUGE REV. A(weather and vibration resistant for exposed environments)Wiring:GND - Connect to a main ground location.PWR - Connect to fused switched 12VDC power. (An accessory terminal will work for this.)DIM - Night Dimming: provide 12VDC to dim displaySND - Voltage measuring point, usually jumper over to the PWR terminal.Mounting:The gauge requires a round hole 2-1/16” in diameter. The gauge should be inserted into the opening fromthe front and the U-clamp will be installed from the back. Tighten the two nuts on the U-clamp so that the gauge issecure. Gauge depth to the back of the case is 1”. Gauge depth including the mounting studs is 1-7/8”.Factory settings:Lo warning point: 11.1VDCHi warning point: 15.4VDC The voltage gauge will light with 8.0 – 17.0VDC on the PWR terminal. The SND terminal can monitor voltagesbetween 1.0 - 18.0VDC if monitoring another source.. The gauge has a user adjustable lower and upper warning level, which can be set to indicate low voltage andovercharging conditions.The SND terminal is the voltage sensing input. To read the vehicle system voltage, connect this to the PWRterminal. To read the voltage at a second battery or other remote location, connect a wire from the SND terminal tothe voltage to be monitored.+12V key on(Switched power)Headlight switch(Optional)