Voltage gauge terminals

[bkwapisz]

I just got a voltage gauge for my boat (which is in storage for the winter,) and I'm looking at the back of it and I'm a little confused.

I must have hooked up dozens of automotive voltage gauges in my time, but this one has a few extra terminals. One is marked "G" which should be the ground. Another isn't marked at all but it runs directly to the light bulb, so that one I know. The question is the last 2, one of which is marked "I" and the other is marked "S"

Which gets the hot lead? What's the other one for?

Any thoughts would be appreciated. I know I can put a hot lead to these to see which one makes the gauge work, but I am wondering about the purpose of the other one.

Thanks in advance.

Brian.

 

[Barnacle_Bill]

Re: Voltage gauge terminals

I terminal goes to ignition. S terminal is not used. They use those cases for other applications like for a fuel gauge. That's why it's there.

 

[bkwapisz]

Re: Voltage gauge terminals

I terminal goes to ignition. S terminal is not used. They use those cases for other applications like for a fuel gauge. That's why it's there.

Thank you, sir!

 

[Silvertip]

Re: Voltage gauge terminals

"I" is the "hot" or +12 volt terminal when the key is on. Simply connect it to the "I" terminal on any other gauge. No need to go to the switch.