voltmeter says connect 2 wires but there are 3 terminals?

[wade]

OK so I've been reading how to connect this Autometer Voltmeter up and I know this should be simple. I have found folks saying connect one to ground and the other to an "ignition on" power source. But why are there 3 terminal? ground, I know that one, "I" I assume for ignition. and then there's "S", where does that go?

voltmeter.jpg

You can see in the pic there are 3 terminals for wiring this.

Another question about the ignition wire, where should I connect that too exactly, I don't want to hack up any wires and splice into my wiring, should I run it to the solenoid? the solenoid has an "S" and "I" terminal, should I run both wires there?

I'm still trying to learn about how automotive wiring works and I appreciate any help.

Thanks!

Wade

[390Nut]

ground is obvious, "I" goes to a SWITCHED 12v source. I say switched, because you don't want the voltmeter hooked up to an always hot, draining the battery when it's not running.

You can tap in anywhere you want, the radio power lead, off the ignition switch, or preferably look for a blue wire going nowhere under the dash. That should be a hot wire when the ignition switch is on only.

No idea what the "S" terminal is for, I can't find anything about it in a quick search. Going to guess here and say that Autometer is saving money and using the same gauge housing for multiple gauges, because the "S" terminal is usually for the sender, like for water or oil temp gauges.

[mkpj1]

Positive, ground, and one for the light.

[mkpj1]

Sorry, pic didn't load,..? "S" would give you cranking voltage and would give you running voltage??

[bluef250]

This site said not to use th "S" terminal
http://www.marineengine.com/boat-forum/ ... alternator

What brand of meter and what do instructions say?

[robroy]

Good evening Wade,

I think it's just as Paul said; the "S" terminal's probably only there because Autometer used the same gauge housing with a number of different gauge types.

I just finished installing my Teleflex/V3 voltmeter, and just like yours, it had an "S" terminal. Yet V3 put a red plastic cap over the terminal to keep it from being used. Thankfully, I only invested minor effort in to removing that cap before reading the instructions--it didn't want to come off!

Robroy

[wade]

Thank you for the responses. The "S" terminal is not used and I got it hooked up. on my '67 I found a blade terminal to connect to on the fuse block and it works great.

Wade

[bluef250]

Does the "S" terminal work? If so, how does it compare to the "I" terminal?

The "S" might be used to continuely monitor the batteries condition during start. For trucks that sit, that feature might be handy.

[wade]

Does the "S" terminal work? If so, how does it compare to the "I" terminal?

The "S" might be used to continuely monitor the batteries condition during start. For trucks that sit, that feature might be handy.

The instructions that came with it do not even mention the "S" terminal. they just tell how to hook it up with the ground wire and the "I" terminal.

So it must just be the same casing used for several applications and in this application one of the terminals is not used.

Wade