I hear people talking about using a volt meter in place of an amp meter for monitoring the charging systems. I don't understand how measuring voltage is going to tell if you are generating amps to re-charge the battery. Can some one explain this??? Where is a volt meter attached in a ford flat head V8 ????
Voltmeters have replaced amp meters in most cars these days. The reasons are many but mainly due to the possibility of electrical fires due to current passing through the wires to and from the guage, and the fact that systems can be monitored more effectivly with volt meters. If you have a volt meter on a system (say 12 volt for discussuion) the system should be putting out over 12.8 volts which is what 12 volt batteries have .If you have a volt meter and see OVER 12.8 volts when you are driving you know that the system is working. Normal range is somewhere between 13.2 and 14.5 depending on your application. Conversely if you are charging way over 14 volts consistently you might be about to have a problem. Voltmeters ALWAYS allow you to spot trouble way before it becomes a problem if you know how to interpret the data.Amp meters show current flow, but are not nearly as accurate or safe. You can hook up the volt meter to any "hot" wire that is handy, preferably it should be through a switched component. That means that the volt meter is working only when the key is on. Over the years I have had 2 Stewart- Warner amp guages fail causing a lot of wasted time trying to trace the problem when it was in the guage itself.I hope this helps.
The Jalopy Journal
