Battery not charging

[JFS]

Just discovered the battery on my AC710, K241S 10HP engine is not charging. I installed an electric lift and after just a short use it stopped working. I removed the lift and connected it to another battery and it worked fine. I then checked voltage at the tractor battery 12.07 with motor off or with it running at 3000RPM. Not sure what size or type charging system I have. Would appreciate any suggestions. Thanks

[G.Kiebler]

I'll bet you have fried the stator.I did the same thing to to my boat motor after installing a cigarette lighter. if i had to guess,the chargeing system probably isn't much more than 10-12 amps.Did you check for a fuse somewhere around the amp gauge or rectifier?

[JFS]

I understand the Kohler K series engine has several types of charging systems for battery ignitions 1.25 amp, 3amp. 10 amp, 15 amp and 30 amp. I don't know which I have. I think it must be at the lower end. I dont see any blown fuses or bad breakers. The important thing now is determining what charging system I have because the troubleshooting in the repair manual is a bit different for each. I don't see a rectifier/regulator on the engine and haven't located a diode. Anyone else out there have a 1979 AC710? What size charging system do you have? And how can I determine what size mine is?? Thanks

[Dutch]

If you don't have a regulator / rectifier (may be hidden behind battery) you probably have the smallest (unregulated) system. The only way I know of to actually confirm what you have is to email Kohler with the engine "spec" number. The bad news is, if you have the smallest system, it wouldn't support the operation of an electric lift or electric clutch for any length of time. Just like a bank account, you can't "withdraw" more than you "deposit".

[JFS]

Dutch, that was my next concern, I have a 36" tiller on this tractor and just ordered a Johnny Bucket JR. I wanted to be able to use the electric lift for both. I think the lift pulls about 22 amp at full load capacity. Now I'm wondering if I should cancel the JB...I'll email Kohler tomorrow with the spec number which is 46764D. Any other suggestions?

[Dutch]

You could upgrade to a larger capacity OEM system, or add an internally regulated (one wire) alternator from an automobile. I won't recommend it, but you could install a heavy duty battery and use the lift until it went dead. Then recharge it in the shop. That's a sloppy and frustrating way to go though.

[JFS]

Word from Kohler indicates I have a 3 amp charging system on my tractor. Now I don't want to seem to dumb but the troubleshooting instructions for that system instruct you to remove the charging lead from the battery for some of the tests. Are they talking about the positive lead or what? Also what is meant by OEM system? Below is my wiring diagram. Need your help. John has agreed to hold up on my JB Jr. Thanks John

[cranemech]

Evening John, OEM - original equipment manufacturer Later, Chad

[BLT]

From what I can see on your wiring diagram, you would have to make your voltage checks by disconnecting the fuse and getting your readings from the wire that runs towards the engine. If you disconnect any other wire, you take away voltage from the coil which you need to run the engine. Dutch makes a lot of sense by maybe putting on a automotive alternator with the single wire. If you elect to go with a bigger charge circuit from Kohler, you might have to get a different flywheel that has more magnets to handle the extra amperage output plus get a voltage regulator, not to mention the new stator winding. If you have the room the adding of a Delco 10SI (Thats the on I am most familiar with)with a 2:1 speed ratio would handle anything you want to do the JD and tiller lift. Its one wire to battery plus it needs a field voltage on run, generally a tap off the igniton wire. The problem is where to mount it.

[jlasater]

Looks like a broken fuse holder was the problem on my 716H which has the same charging system. The origional barrel type fuse holder was cracked and broken in half, in addition to having a blown 10A fuse. The fuse is supposed to be 5A. I replaced it with a blade-type fuse holder, similar to what cars use nowadays. When the engine is running, the ammeter reads 0 whereas before it was always -3 or so showing a draw by the ignition system. If I pull the fuse, it again drops to -3, so I think that has my tractor taken care of. As BLT said, I tested by pulling the fuse out of the fuse holder and hooking up my DVM to it, read about 35VDC which the book says is fine (28VDC or better is good on the 3amp charging systems.)

[EDS]

John, From your wireing diagram, I see an AC output for the lights. This looks like a alternator you use at night only. You could run the AC to a bridge rectifier and the output to the battery. You might want to add a voltmeter and a switch to make sure you don't over charge the battery. Never let a battery go higher than 14.5 volts. You could also use a regulated rectifier like that for the 15 Amp system. The more I think about your battery power management problem, the more I think a Volt meter in addition to the Ampmeter will help you to know if your battery is charged or not. Make sure you have a fresh and lagre battery.

[BLT]

EDS If you look at the wiring diagram closely, you will see it has a DC circuit for the battery, the one with the 5 amp fuse and an AC circiut for the headlights, as the bulb don't care if it is AC or DC. Common circuitry in garden tractors. And when you do windings check to see if it works the voltages are fairly high.

[JFS]

"UPDATE" I checked the stator OK, 36 Volts at about 1500RPM and 56 Volts at about 2800 RPM. The diode also checked out OK with resistance about 1.3 Ohms. I concluded that by my replacing the ignition switch and rewireing the connections earlier I had failed to connect the charging wire back to the battery with the ignition in the run position. I decided to order the correct ignition switch from Jacks Small engines last week. Hope to get it in a day or so. I am hoping that with the 3 amp charging system finally working and only periodic operation of the electric lift that the lift will perform OK. Upgrading to a larger OEM charging system is quite costly and putting on an alternator (making brackets and such may be beyond my talent, I'm not a welder unfortunatly) was also told by a local delco auto electric shop that installing the auto alternator could cost several HP on a 10 HP motor. Will repost when I get the switch.

[CarlH]

The local auto electric shop is right about the potential for a horsepower drain when you have a significant electrical load. However, note that you use the electric lift relatively infrequently and mostly when you don't have any other large load on the engine. 22 amps at 13.5 VDC with 50% conversion efficiency is about 1.5 horsepower.