60A alternator overcharging test before replacing regulator

[JasonS]

Many have posted difficulty with their alternator overcharging and attributed this to the regulator. I encountered this recently (on alternator after alternator) and discovered that the fault was not with the alternator/ regulator. This alternator uses the excite wire as the voltage sense lead. If there is an intermittent/ poor connection and the regulator sees an artificially low voltage, the alternator will increase the voltage to correct. In my case, even though the line feeding the alternator read 24V with a voltmeter, it was sketchy enough to cause the over voltage condition. Before you condemn the regulator, connect the exciter lead DIRECTLY to a known good 24V such as the battery or starter lead and check the output.