A battery indicating 12v (12.4) does not mean it can deliver the amps required to turn the engine. Think trying to start your truck with a brand new 12v lawnmover battery; plenty of volts, can't deliver the amps. A tired battery cant turn the engine, and usually lights will dim at low RPM because the battery cannot help the high load when the alternator output is low.
Analog meters, both voltmeters and ammeters are not real accurate both in display and reading, they have wide sweeps, and indexes far apart. Digital tells you much more, but you are not using these gauges to troubleshoot, only detect a problem to steer you towards troubleshooting before you are stuck with a dead battery.
You could do the voltmeter in the Cig Lighter.
This article was to help Stovebolters that wanted a voltmeter in the cluster for less than $400-$600. And avoid the danger or high loads traveling through an old small capacity ammeter.
Last edited by Mikeybakken; 07/09/2013 3:39 PM.
