C-81 not charging battery

[vette10r 13]

I just inherited a C-81 from my grandfather who passed away. He's had it for 30 years and ive helped him work on it in the past. It starts right up and runs good but only until the battery dies then I have to throw it on the charger again. Can anyone here steer me in the right direction to get this fixed? Thanks

[gwest_ca-(File Mod) 11,393]

Welcome to the forum.

Do the simple things first.
This model has a 15 amp charging system.

Check voltage across the battery posts with the engine not running.
Then start the engine and see if the voltage increases and to what voltage.

Check the terminals at the voltage regulator and the plugin connector to make sure they are clean and tight.

Turn the key to ON without the engine running.
Check the voltage across the battery posts. Red to (+) and black to (-). Take note of the DC voltage.
Now move the red lead to the DC+ terminal on the voltage regulator. You should have the same voltage and if not fix that. This checks the path the charge current takes to get to the battery.
Another reason to make sure this is good is these regulators require battery voltage before they will regulate the charge current.

The aluminum body of the regulator requires a good ground which is accomplished by the mounting bolts. On older tractors the chassis often looses the ground through corrosion. You can add a ground wire to the mounting bolts and a good known ground like the battery ground cable - either end.

Next is to check the AC voltage across the other 2 stator wires at the voltage regulator. Pull the connector off to check. Should be more than 28 volts AC with the engine running. Rev it up.

A Kohler service manual
http://www.wheelhorseforum.com/files/file/3450-engine-kohler-k-91-k141-k161-k181-k241-k301-k321-sm-1972-hrpdf
Download this file
Kohler 4-72 SM Section 07.7-7.12 Altenator charging systems HR.pdf

Let us know what you find.

Garry

 

[rmaynard 16,217]

Dittos on everything Garry said. In addition, I would add that the C-81 is a cradle mounted engine. All the engine grounds run through the cradle, and then the cradle is grounded by one 6 gauge wire from cradle to frame. Make sure that all your grounds are good, especially that one.

[vette10r 13]

Thanks for the great info guys! Im at work right now but will try this out when I get home and report back!

[vette10r 13]

Just wanted to ad that I looked over the grounds and the large ground wire that comes off the "alternator" (at least thats what it says on it) was barely hanging on. I took it off and got new lugs then re-installed. I ran the mower and cut both the front and back yard a couple days ago and its been sitting since. I grabbed my multi-meter this morning before work and put it on the battery and it read 12.54 volts. Im not sure how much the mower drains the battery running for a half hour but Im hoping its fixed now!?