LB1914 Wont Charge. Regulator? Alternator? Multimeter Question...

[shaw1ak]

Hello Everyone,

This is my first post so thank you in advance for any insight.

I just put in a new battery, however, my "lighting bolt" / "charge" light is on while running. Yesterday after mowing for 2 hours, it wouldn't start once shut off. I checked my battery and it read ~12.4 volts. I checked the battery again while running @ 2000 RPM, after i put it on the charger on, and it read ~14.5 volts. Is this in the expected range? How can I trouble shoot my Regulator and Alternator with my Multimeter? My shop manual is missing the charging system diagram, conveniently Any advice on how to trouble shoot these two components, or other advice is greatly appreciated!

Thank you,
Ashton

 

[Clint S]

That sounds about right. When you checked it when it would not start did you check the battery voltage when you tried to start it to see if voltage dropped ? The light is on when you tested it at 14.5 volts??

 

[CalG]

That sounds about right. When you checked it when it would not start did you check the battery voltage when you tried to start it to see if voltage dropped ? The light is on when you tested it at 14.5 volts??

I agree, those are good numbers. 14.5 V is a good regulated output.

The process I use with a Voltmeter.

Across the battery terminals with everything off. (12.5 or so)
Across the battery terminals with key on, and some load like the head lamps. (ding a volt )
Across the battery while operating the self starter (> 9V, more is better ;-)
Across the battery with the alternator spinning just over a "fast idle" (14.5V)

Then I like to measure from the battery + POST to a good ground, followed by the + CABLE clamp to the same good ground. (should be EXACTLY the same)

Look for bad connections between the battery and the starter, don't neglect the solenoid.