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MarkB_MI 01-22-2013 03:01:19 75.198.98.60 Report to Moderator	As I see it, the biggest problem with running the original ammeter on an alternator system is voltage drop through the original wiring. If I was rewiring a tractor for a 12 volt conversion, I'd go with a voltmeter because it's simpler to wire than an ammeter and allows the alternator output to be connected directly to the battery with heavy gauge wire. Which is the main reason ammeters disappeared from passenger vehicles forty years ago: high-capacity alternators required a remote shunt for the ammeter, which adds cost and complexity. A voltmeter requires a single small-gauge wire to a source of 12 volts and a ground. As a diagnostic tool, I prefer a voltmeter. A slight discharge is difficult to see on a ammeter, but is obvious with a voltmeter. It's difficult to detect a failed diode or regulator with an ammeter. [Reply]   [No Email]
Hobo,NC 01-22-2013 04:55:05 71.30.81.18 Report to Moderator	Re: Amp vs Volt Gauge in reply to MarkB_MI, 01-22-2013 03:01:19   Whut he said,,,, every time I have pinned a amp meter lubber down they seam to get tong-tied answering a simple diagnostic question.... I will leave my amp-meter in my box till I need it but the first thing I will tote with me to diagnosis a no crank no start is a voltmeter... [Reply]  [No Email]
RodInNS 01-22-2013 09:17:13 216.118.158.123 Report to Moderator	Re: Amp vs Volt Gauge in reply to Hobo,NC, 01-22-2013 04:55:05   They both have their place. I mostly use a voltmeter for diagnostics. When you know how to read the nuances of the meter you're using it generally tells you about all you need to know. As far as I'm concerned, in terms of a charge reference on a machine with an alt... the old idiot light is as good as any. An ammeter can also give you a lot of good info tho.... very quickly show you a discharge situation if it's wired correctly, belt slip, no charge, etc. IF you know wht you're looking at. The main thing I use an ammeter for (current clamp) is checking starter draw. For that, it's indespensible. Rod [Reply]  [No Email]