?

AMP Indicator in the 122 instrument cluster does NOT indicate amps, and an AMP meter cannot simply be connected "directly to the amp light", George is absolutely correct here...DON'T DO IT!

If your conversion is a SwEm kit, check out the wiring diagram with kit which includes specific info on connecting an AMP meter. If the alternator was installed by you or persons unknown, you're on your own because we have no way of knowing what you have, and what was changed when the conversion was performed.

I have to disagree with George that a Voltmeter "will tell you just as much or more about your charging system." A voltmeter (even an expanded range type) is a single area indicator...that is, it tells Voltage only, and that is pulled up or down by the loads and charging system...what it indicates when things are working fine can be all over the place! Besides, from 0% to 100% battery charge spans a mere 0.8V.

It can be argued either way, and I will agree that a Voltmeter is infinitely better than an "Idiot Light" only, but I prefer to know the state of what is happening at the battery...is it being Charged?...or Discharged?...and the fact that an Ampmeter is a zero-center indicator will tell me that...if I see Discharge any time the engine is running, I have a pretty good idea that the charging system is not working...long before the battery is dead.

...and I also have to disagree with Derek...there is no inherent technical reason or advantage to associate an "Ammeter with dynamo/generator and Voltmeter with an alternator". Either can be used with either just fine...the trick is to understand what each is telling you!

Suggested reading: http://www.sw-em.com/elecramb.htm

You should understand what Ampmeters and Voltmeters do and how they should be connected before attempting to connect either to your vehicle's electrical system!...otherwise engage someone who does...including contacting me off-line.

Cheers