I have two gauges to install, Boost and Water Temp. They are Innovate Motorsports G2 gauges, silver with a clear lens.

Both gauges have these wires:

Black - Ground
Red - 12v (+) Ignition Source
Orange - connect to 12v (+) dash circuit for Amber back lighting
White - connect to 12v (+) dash circuit for White back lighting

(The water temp gauge also has Green for the sender's signal)

QUESTION: If I connect the Orange wire for 12v (+) so that I get amber back lighting at the same time as the rest of the dash, why would I also need the Red 12v(+) from the ignition?

 

The red +12v ignition powers the gauge , the +12 volt for the lighting only powers the LED back light

 

OK, the temp gauge, I can understand needing to be powered, but the boost gauge? It works if I blow down the hose.

 

The boost gauge still needs to light up at night. The black is ground, and the orange will allow it to dim with the OEM gauges. Red should be main power.

 

Got it all working, thanks.

 

got 'er done

 

Looks good!