Is there a simple way to test the alternator on a yardman riding lawnmower with Kohler 16 HPengine?

Answer 1

Testing Alternator Output on a Riding Mower Engine

I do it with a handheld VOM [Volt-Ohm Meter]:

• Plug the red test lead into the Positive [+] jack in the meter.
• Plug the black test lead into the Negative [--] jack in the meter.
• Set the VOM mode switch [usually a "rotary" type of switch] to the 50 Volt DC [Direct Current] mode/scale.
• Place the meter next to the battery so you can read it while holding the test lead probe points to the battery Positive and Negative terminals.
• Touch and hold the red Positive probe to the Positive terminal on the battery.
• While holding the red lead in contact with the Positive terminal, touch the black Negative test probe to the Negative terminal of the battery.
• While holding the probes in good, firm contact with the battery terminals, observe the meter readout or display to determine the voltage in the battery.
• Either remember, or record that voltage reading.
• Then, with the blade disengaged and the transmission in neutral , AND the parking brake set, start the engine, and set the throttle to wide open.
• Now repeat the voltage test of the battery again.

If the magneto/alternator is working, the voltage indicated on the VOM should be greater than the battery voltage without the engine running.

If the magneto/alternator is working properly, the voltage indicated should be at least 12 1/2 volts, and not exceed 16 volts.