Mend > Lawn Mowers

Battery not charging on Craftsman 16HP mower?

I put a new battery and voltage regulator on the mower. It still won't charge the battery. It will run fine from a boost till I shut it off. How do I test the charging system?

Andy Koornneef
May 2006

Craftsman Garden Tools, Lawn Mowers Battery Not Charging

I take it that's a Vanguard engine.
The voltage from the alt should be no less than 26 Volts AC
so your getting that OK Are you getting a DC current to the battery out of the regulator? Check to see that the regulator has a good ground. If the wire to the battery still shows no current the regulator is most likely bad.

Rick
May 2006

Thanks Rick. It's a Model 303888. I tested the fuse and it's good. I tested the voltage from the Alternator and it's at 27V AC. Does that seem right? Could it be that the starting solenoid is bad? I don't see anything on the wiring diagram about an inline diode. Would it be in the voltage regulator?

Andy
May 2006

If it's a Briggs engine there are 11 different types of alternators. Not knowing your engine Model Type and Code I can tell you a couple things to look for. Some have an inline fuse , and some have an inline diode. If your has either of these one of them may be bad. As for testing, some are DC and some are AC. Totally different setting on the test meter. Can you give the Model Type and Code numbers?

Rick
May 2006