Kohler CH740s Not charging.

[enamel 35]

Not sure what's going on. But put a new stator and rectifier on it and still no charging. I'll try and test from center tab for output on the rectifier prob tomorrow. 

Its in a Grasshopper 227. 

Seems almost like a wire is missing. 

I have large red from battery to starter. And a blue one for the solenoid of the starter. Think a red fused on also from starter lug but can't remember where it went. 

 

Wheres a good place for a wiring diagram for the charging ? 

[enamel 35]

So I was curious and checked the AC output on new stator. No reading on meter. 

Fun

[peter lena 8,960]

@enamel  suggestion , have any alligator clip test wires ?  easy to make up ,  battery ground bolt point , as ground  source , run other end to RECTIFIER , mount mount bolt / screw , on engine cooling tins . that poorly  grounded spot is a common electrical  fault zone . also like dielectric , grease , Pete

[gwest_ca-(File Mod) 11,169]

 

[953 nut 56,613]

The center tab of your regulator needs to have 12 volt DC battery voltage to it to work. The outer two tabs should read 30 - 36 volts AC between the tabs and no reading to ground. The manual Garry attached should be helpful.

[Handy Don 12,980]

Regulator needs very solid ground and the battery connection.

Edited September 30, 2023 by Handy Don

[enamel 35]

When I tested stator output I had the plug undone and probes in the plug and mower running 

[953 nut 56,613]

You need to connect the plug to the regulator and test the input/output with the engine running at half to full throttle..

[enamel 35]

1 hour ago, 953 nut said:

You need to connect the plug to the regulator and test the input/output with the engine running at half to full throttle..

Can't its buried behind a pump for steering. It's a zero turn. 

But shouldn't the stater be putting out AC regardless if plug into the rectifier or not ? 

[enamel 35]

I forgot new stator has a long pigtail (holding it in the picture)  So I guess I can test stator input while plugged in. Idk about output tho because there's a cooling fan and hydraulic lines right next to the rectifier. 

[Gasaholic 238]

10 hours ago, enamel said:

I forgot new stator has a long pigtail (holding it in the picture)  So I guess I can test stator input while plugged in. Idk about output tho because there's a cooling fan and hydraulic lines right next to the rectifier. 

Huh?  From that photo, you only have one stator wire hooked to the connector?  You need both wires coming from stator to get a reading - in your case, appears to be two black wires, the "pigtail" you are holding appears to be the wire harness wrap that BOTH wires should be routed through - You'd need to test output across both wires , and in your flat 3-pin connector, those 2 wires hook to the two outermost sockets of the connector... This would explain why you're seeing 0 volts while doing your stator test. 

 

Just based on what I am seeing in the photo 

[enamel 35]

1 hour ago, Gasaholic said:

Huh?  From that photo, you only have one stator wire hooked to the connector?  You need both wires coming from stator to get a reading - in your case, appears to be two black wires, the "pigtail" you are holding appears to be the wire harness wrap that BOTH wires should be routed through - You'd need to test output across both wires , and in your flat 3-pin connector, those 2 wires hook to the two outermost sockets of the connector... This would explain why you're seeing 0 volts while doing your stator test. 

 

Just based on what I am seeing in the photo 

 

What I'm holding is both stator wires.  The one wire you see (purple) is the DC output. The black is the rectifier case ground. 

Edited October 1, 2023 by enamel

[Gasaholic 238]

Ah. OK. well if you can pull those wires out far enough to connect test leads (red to one black to the other) and run engine, your stator should be putting out something like 28 -35 volts AC voltage @ full throttle  If you do, stator's fine, if you still get 0 volts that way I'd be checking the flywheel magnets and stator winding resistances (It was not uncommon for those flywheel magnets to come loose from their epoxy mounting and just sit there, but they shift around - at least until something causes a magnet to catch on stator and the whole thing grenades...)   There isn't much else if anything that would cause 0 volt output from stator, otherwise.  If you can verify that , and then hook stator wires to connector and connector to regulator, then your purple DC+ wire should have more than 12V (up to 14.8V) output when engine running. - don't need to access regulator directly, just need access to the wires that can reach regulator.  If you can verify stator output but can't verify DC output, chances are a bad regulator (Or, connections to regulator are not making contact, or broken wire(s) between regulator and your test point) 

[enamel 35]

I guess what I'm not understanding is this. 

If the stator is making power when the motor is running. That to me says theres output on the 2 stator wires at the plug. 

So I'm not understanding why it needs to be plugged in. 

I watched a few vids testing the output and the videos showed the person unplugging the plug. Probing the 2 outer wires. Starting the motor and had results on multimeter. 

 

 

Also I dodnt check the magnets when I took the flywheel off. Never occurred to me lol. 

 

Edited October 1, 2023 by enamel

[Handy Don 12,980]

Yes, if the engine is running (presumably using a battery to power the coil) and the only thing you want to test is stator output, then yes you can test for AC voltage across the two stator wires.

I would first check for continuity between each stator lead and ground. Should not have continuity--infinite ohms.

I would next check for continuity across both leads. Should have continuity--near zero ohms.

I would next get the specs for the stator and check the resistance. There should be a small resistance (less than 5 ohms?)

THEN I would check for AC with the engine running. With the engine at half speed or better, expect 20-40 VAC.

 

Edited October 2, 2023 by Handy Don

[enamel 35]

Testing between each stator wire and ground. Ground being like a holt somewhere ? And red prob to the stator wire. 

[enamel 35]

Ok first picture is the ohm test on both stator wires. 

 

2nd picture is battery ground to rectifier ground ohms. 

 

No pic. Tested  each stator wire with ground. No reading. 

 

[Handy Don 12,980]

14 hours ago, enamel said:

 

Ok first picture is the ohm test on both stator wires. 

 

2nd picture is battery ground to rectifier ground ohms. 

 

No pic. Tested  each stator wire with ground. No reading. 

 

1.5 is very probably fine for the stator coil resistance (I don’t know the exact spec for that machine)

No shorts to ground is also good.

Assuming you get AC voltages when the flywheel is turning at 2500-3000 RPM, you can stop worrying about the stator and focus on the connections and the regulator! 

Edited October 2, 2023 by Handy Don

[enamel 35]

3 hours ago, Handy Don said:

1.5 is very probably fine for the stator coil resistance (I don’t know the exact spec for that machine)

No shorts to ground is also good.

Assuming you get AC voltages when the flywheel is turning at 2500-3000 RPM, you can stop worrying about the stator and focus on the connections and the regulator! 

 

When I test the stator leads while motor is running I don't get a reading. Plug unplugged. Rectifier is new also. 

[Handy Don 12,980]

5 hours ago, enamel said:

 

When I test the stator leads while motor is running I don't get a reading. Plug unplugged. Rectifier is new also. 

Apologies if this is a dumb question, but you do have your meter set for AC in the 0-100 VAC range and securely connected to the leads, right?

So if the stator has good readings but no juice comes out when the flywheel is turning at a good speed (i.e. WELL above idle) then it’s time to suspect that the magnets inside the flywheel are not in their correct positions to induce current in the stator coils.

Have you had the flywheel off?

[enamel 35]

It's OK ask anything never a dumb question lol. 

But I've tried all the settings for AC while motor running. Connections were good. And I'm leaning towards magnets also. I shoulda checked them while I had motor out changing the stator. 

 

[Handy Don 12,980]

5 minutes ago, enamel said:

It's OK ask anything never a dumb question lol. 

But I've tried all the settings for AC while motor running. Connections were good. And I'm leaning towards magnets also. I shoulda checked them while I had motor out changing the stator.

I try to be cautious because one doesn’t always fully understand the competency a poster is bringing to the poblem!

That setting is for DC. The V~ symbol in the upper right indicates the 200 and 600 ranges are the AC ranges. That said, if the stator were generating anything, the DC range should show something .

I missed earlier that you’ve replaced the stator. How sure are you that it was the correct stator? Did the number and arrangement of the coils match exactly what you removed? A wrong stator not aligned properly with the magnets might not give any output!

[enamel 35]

I had gotten the oem.part number from Kohler then found one on Amazon. Sec ill get that info. 

[enamel 35]

What I bought

Part number oem

Pic of my old one. 

[Gasaholic 238]

Yep. what Handy Don said - You got your meter set on the wrong scale to check stator output - You need it on AC volts, and measuring the 2 probes across the 2 stator leads (On your meter you want it on a scale under the V~ - the squiggly line which represents Alternating Current, not the Dash/Dotted one, representing Direct Current)