hooking up a voltage gauge on a bike to watch voltage while riding it is a small 1.5 inch gauge. on the back it has + - and S terminals. whate does the S terminal hook too? + and- turn on the light and it reads almost 14v. does the S terminal hook to the voltage reglator? i know kind of a dumb question but a buddy wanted me to put this on his handlebar

randy

 

the "S " lead is for a Sense wire , It's used to zero out any voltage loss across the length of the wire used for the monitoring wire. It's usually only found in critical electronic circuits. Ideally, run a wire from it to the exact same place you're monitoring the voltage at. If you left it disconnected, you'd probably only see a 0.1 volt different reading on your meter.

 

this is on an old ironhead sportster with an alternator upgrade i just hooked + to the hot sied of battery and - to ground is that ok The face lights up too
randy

 

that should be fine for what you want