switched 12V current goes the the VL & is reduced to a pulsed ~5V then to the respective input terminal(s) on the temp and gas gauge(s) then from the "out" terminal on each gauge downstream to the respective (eng block/gas tank) senders. hot temps/full tank lets more current thru moving the gauge needles further to the right toward H/F. I wasn't quite sure where to start on yours' so I just thru some stuff out there to get us started & get it pinned down a bit. Nah I ain't going nowhere, it's too cold and I'm too lazy