2005 Walker MTL 25HP not charging battery

[johnstern]

The title says it all. I have cleaned battery terminals and the terminals on the circuit breaker just behind the battery. This helped a bit but voltage across battery with engine at full speed is 12.04 volts. Did visual inspection of all wires and saw nothing unusual. Cleaned entire engine with compressed air (I usually do that after each mowing anyway) and did find some unseen dirt at rear but no change.

I am able to mow my whole lawn on the battery.

Any suggestions

 

[johnstern]

OK! So after some research I know that I have to read the AC voltage (should be 28 volts AC) being generated at full throttle by the stator/flywheel alternator at the two white wires connected to the voltage regulator/rectifier.

My question is where is the regulator/rectifier. Is it inside the finned aluminum box located above the starter motor? If not there, where is it?

Thanks.

 

[ILENGINE]

On kohler it is opposite the starter in the blower housing. Kawasaki normally is in the blower housing also. Both have three wire connectors.. Briggs is located on one of the shields around the cylinder, and has a two wire and a one wire connector most of the time.

 

[johnstern]

On kohler it is opposite the starter in the blower housing. Kawasaki normally is in the blower housing also. Both have three wire connectors.. Briggs is located on one of the shields around the cylinder, and has a two wire and a one wire connector most of the time.

Thanks for your help. I'm going to work on it tomorrow if my desk work doesn't get in the way-UGH!!

 

[johnstern]

Finally got to work on the Walker late this afternoon. The regulator/rectifier is a finned aluminum device bolted to a bracket (2 bolts) located on the exhaust side of the engine (the opposite side of the engine from the flywheel) half under the cooling fan shroud. I removed the shroud (2 bolts and 3 Phillips head machine screws) to get better access to the regulator/rectifier mounting bolts. I removed and unplugged the device and probed the 2 white wires on the engine side plug with my DMM and started the engine.

At full throttle the voltage across the white wires was 42.2 volts AC, well within the "28 volts or more" spec and the voltage increased/decreased smoothly as I revved the engine. I got this spec from the Kohler Aegis LH 685 engine manual I downloaded for free on the internet. So, phew, the stator is OK. I'll call the local Walker dealer tomorrow to see if they have a regulator/rectifier in stock. I am very sure of my diagnosis but I hope to have them test the regulator/rectifier if they have a tester just to make double sure. :thumbsup:

I'll be back to post the final results.

BTW-after the testing, I reinstalled the cooling fan shroud and mowed my lawn on the battery. It only takes about a half hour and afterwards I put the battery on the charger.

 

[johnstern]

Monday morning I called the local Walker dealer to find out if they had the voltage regulator/rectifier in stock and they did-part #25 403 23-S for the 25 amp system. Tuesday I picked up the part and they tested my old on and found it to be "junk".

Installed the new regulator/rectifier in the Walker and all is good. Battery charging at 14+ volts.:smile: