Installing an Ammeter, Amps / Gauge / Wire Options

[Jaws4God]

I just ordered an Ammeter gauge for my car since I had some problems with my alternator going bad and not knowing because my volt meter read 12 volts...

Does anyone have some tips on how to install it?

Thanks!

This post has been edited by Jaws4God: Jan 23, 2007 - 10:45 PM

[Mangozac]

OK after some checking out the situation it's like this:

The manual says not to have the starter motor going through the ammeter. Which in retrospect is fine because you don't really need to know what the starter motor is drawing (because it's only on when you crank the engine). So you will just be measuring everything else. I'd be surprised if your alternator will put in more than 60A - but it would be good if someone can confirm this.

Even without including the started motor it will display the way you want it to. And tell you if the alternator is bad.

Your ammeter has an internal shunt resistor. This means that all of the current has to flow through the meter. I don't really like that idea because it means running a fat cable from the battery to the gauge and then back again

You'd be better off with a gauge that uses an external shunt. That way the shunt goes in series with the battery and you simply run some little tiny wires between the shunt and the gauge.


On a side note a friend of mine is trying to talk me into making a little digital gauge that uses a full colour LCD like display. It would be able to show stuff like current but the coolest idea we came up with for a feature was including an accelerometer so that it could display the G forces that you are pulling in both fwd/back and sideways directions. Sure, it wouldn't be many Gs, but it would be cool/fun to see! But it would require a good chunk of time to do, of which I'm very short on these days...

This post has been edited by Mangozac: Dec 13, 2007 - 9:34 PM