Battery light comes on after 30 seconds
I have an ‘05 Mariner (V6). The alternator was not charging my battery (battery light on and alternator output would only go above 12 volts if the engine had high RPMs as measured with a voltmeter on the battery, the the battery light would go off).
Just got through replacing the alternator, and was happy to see the meter indicating 14volts and battery light off. However, after exactly 30 seconds, the battery light comes on even though the battery is still receiving 14 volts. Shut the engine off, start it back up, and EXACTLY 30 SECONDS later the battery light will come on, every time, even though the alternator output is good.