which AMMETER is correct???

Please help

John

As far as the Volt/Ammeter discussion goes, both are useful devices however neither alone will tell the whole story of an electrical system.

The volt meter will tell you how many volts are in the system. If the charging device is in good working order it will show around 14 volts (+ or – a bit) while the engine is running and then settle back to around 12 to 12.5 when it stops. If there is a 3 amp drain in the system, the voltage will not drop enough on a volt meter to be noticed. Likewise, if the voltage regulator is starting to get bad, the ammeter may set on 0 or up an amp or two looking normal but the charging device may be putting out less than 12 volts.

To get the complete story on a charging system you need both ammeter and voltmeter. However, the ammeter is the more common and in my opinion the more useful of the two in day to day operations.

The real deal is to install a voltmeter. I presume you are using a 12 volt system. A voltmeter should be easy and inexpensive to install.

A voltmeter doesn't tell you bupkus about what the charging system is doing. An Ammeter will tell you whether the system is charging or discharging at any given moment.

If your ammeter is reading 0 or a very slight positive charge, your battery may well be sitting there fat, dumb, and happy with a whopping 10.5 volts in it - depending on circumstances.

I assumed the battery was good. Even an ammeter will not detect a bad battery.

An ammeter will not tell you if the generator or alternator is overcharging. Only a voltmeter can tell.

What is the first thing Bob M tells someone to do when they ask how to troubleshoot a charging circuit? You will be directed to check the charging voltage with a voltmeter.

Nuff said.