15 year old Craftsman mower issues

[Diggin It]

Got a PYT900 from Sears not too long before they shut down around this area. Has been fine over the years with a few problems.

Briggs 24HP VTwin Vanguard.

Latest issue is charging. Battery has to be on float charger for it to start at all. If it dies or has to be shut off for any reason, it will not restart without a jump.

Test today shows no output to the battery, when tested AT the battery.

I'm not much of a tech, so I'm not sure where to begin. Voltage regulator is $10, two bolts and two plug in connectors. I can probably handle that without breaking anything, but will it accomplish anything? Stator seems to be under the top fan assembly and I'm not sure I have a big enough socket, or the torque to remove that nut.

 

[Snobdds]

A coil or magneto only provides enough current to fire a spark plug. They are not similar to an alternator that provides bulk current to charge a battery. Small lawn mower engines do not have alternators

You need a new battery.

 

[kirkawilson]

From memory long ago, I think there is a diode in one of the wires that connect the battery with the alternator. It looks like a wide spot in the wiring harness. That diode can go bad not allowing charging current to flow to the battery.

 

[Diggin It]

Battery has been replaced and tested. It's fine and takes a charge from a separate charger.

Items involved:

"Alternator Stator & Regulator For Briggs & Stratton 592830 696458"

Ring mounts under the top flywheel (for lack of a better term) and acts as an alternator to provide power to charge the battery and run the electromagnetic blade clutch.

Power must be generated to operate the blade clutch, the battery alone can't do it.

 

[dodge man]

Yes the alternator is just the flywheel spinning.

 

[Diggin It]

But the question remains .... is replacing the VR only likely to correct the issue?

I'm really not sure I have the tools to pull the flywheel.

 

[flyerdan]

Since the battery has been replaced, I'm assuming there is no corrosion on the cable ends? I would unplug the voltage reg and plug it back in, might be enough corrosion in the connector to kill it.

 

[tom3]

Check the wiring going into the alternator, use AC scale. If you see voltage there the regulator is probably bad.

 

[TMGT]

Check for ac voltage between the 2 wires coming from the stator (coil under the flywheel), you'll have to check for particular engine model, but is usually between 28-35v ac at full throttle.

If you have the correct ac voltage going into the regulator and no dc voltage above 13v coming out, it's safe to say you have a bad regulator. Check that the regulator and engine still have a good ground also


If you dont have the correct ac voltage check the charging system wiring for damage and the resistance between the 2 stator wires (once again you'll have look up your specs based on you spec engine), to see if the stator is damaged.

 

[tomplum]

In addition you need there to be battery voltage at the regulator. They are not switched and wired hot. So you depend on the regulator to shut down and you'll have no draw if that part of the regulator is working. Be sure the battery is good to start with. A good battery is capable enough to run the PTO clutch on it's own -probably for a couple hours. Personally, I would opt for the OEM regulator. It has an important job.