312-8 with K301S Possibly not charging

[TC10284 111]

1 hour ago, Tuneup said:

Those systems are not designed to provide adequate charging to a battery that is in its death throes. Did I get that word right? They are designed to keep a healthy, charged battery healthy. It's amazing that the coil fires adequately at 9 VDC. My typical NAPA coil decided to kill my old C-120 when the trash battery (which had easily started it earlier) reached 8.5 VDC. That is with a healthy regulator. These 1/2 rectified systems won't supply the current. That battery is toast. Get a healthy one, charge it and then diagnose the electrical. It might just be perfectly fine.

 

I think what actually happened instead is that I recently changed which solar charger I had it connected to. And the solar panel wasn't/isn't getting much light, and the charge controller LED lights itself may have drained the battery over time. I am going to try to address that. 

 

Gonna charge the battery up, load test it, recharge it, and try the troubleshooting guide again. 

 

 

Side note: I'm not an electrical engineer, but interested in all that and to find this out...

Is the diode on this wire from the Alternator (stator) like a "poor man's" AC to DC converter? The diode keeps the AC voltage from reversing direction, thus creating a (crappy?) DC current enough to charge the battery and run lights? 

 

Edit: After doing a Google search, it does look like that's what they are doing with the diode. Although that then leads me to wonder how the voltage is regulated if it gets past 16v.

But I guess it may not since it's a "3 amp unregulated but rectified system". Very interesting. 

 

 

 

 

Edited October 15, 2021 by TC10284

[pfrederi 18,205]

You are correct the diode cuts off half the AC it is choppy not suitable for electronics .  The head lights are running on AC with voltage varying based on engine speed.  (note how the get dimmer at idle).  That also creates issues if you want to go LED as most 12v LEDs are DC only.  Even hooking the LEDs direct to the battery may only be partially successful as the choppy DC charging may make them flicker..

[TC10284 111]

3 hours ago, pfrederi said:

You are correct the diode cuts off half the AC it is choppy not suitable for electronics .  The head lights are running on AC with voltage varying based on engine speed.  (note how the get dimmer at idle).  That also creates issues if you want to go LED as most 12v LEDs are DC only.  Even hooking the LEDs direct to the battery may only be partially successful as the choppy DC charging may make them flicker..

 

Interesting... I've seen this LED flickering behavior in my 414-8, but that was an M14 Magnum. 

 

Thanks for helping me learn something!

I've always liked electrical engineering, but never taken the dive into it officially. Only hobbies, like small engines. I do IT for a living. 

[Handy Don 13,126]

6 hours ago, Tuneup said:

That battery is toast

 

On the 3-amp unregulated systems, the very low amperage plus the diode cutting off ½ of the output to the battery means the battery is seeing intermittent DC at its + terminal that varies from 0 volts to 13+ volts @ 3 amps max when the engine is at speed. BUT, remember that the battery itself has some juice, so a meter measuring battery + to battery -  will show an average of the the battery's voltage and the charging voltage. 

 

LED Note: Since the DC is intermittent, the LED will try to flash on and off faster than your eye can follow, hence it looks like a flicker. (Added note on the LED -- the "D" stands for diode. Current will flow through only in one direction so if you hook up an LED backwards, you get no light at all!)

Edited October 15, 2021 by Handy Don

[TC10284 111]

Video results of my tests. The last test I need to do is on AC mode instead of DC mode BEFORE the diode. I forgot that one. 

Be sure to note where I move my voltmeter test leads to in the videos. In short, it looks like I got nothin' in DC mode.

This is a freshly charged battery that started with a voltage of right under 13V prior to installing in the tractor. You can see this in the first video in my link. I had the three pin connector disconnected to show you it load tests fine. 

 

https://photos.app.goo.gl/gbNUJLxJ1sjtDbae9

 

I've tested to make sure I can see these videos in incognito mode without having to sign into Google or anything else. 

Let me know if you cannot see them. 

 

Side note: 

The previous battery was fine. The solar charge controller LEDs drained it over time from not getting any sunlight. It charged up fine and load tests fine. 

Edited October 16, 2021 by TC10284

[TC10284 111]

AC mode test:

https://photos.app.goo.gl/dfn6pbk9fUNfaKDZ7

Edited October 16, 2021 by TC10284

[Handy Don 13,126]

17 minutes ago, TC10284 said:

AC mode test:

https://photos.app.goo.gl/dfn6pbk9fUNfaKDZ7

The starting videos say good battery and normal load as it tries to start.

 

In the 36sec one, 12.56 at idle at the battery seems ok but since it doesn't change upward with higher revs, to 14-ish, there I no charging.

 

The 16 sec video showing 50-70 between one side of the stator and ground is on your VOM's mV (millivolt) scale, not the V scale (usually pressing the Func key several times will let you force the scale from "Auto" to a fixed range--watch the label and the decimal point. But the black lead wasn't grounded?

 

The other videos testing between the two stator lines (and on one, before and after the diode) and not getting any significant voltage says you have a problem with the stator or the wires leading to it.

 

I couldn't see where the red lead was plugged into the amp probe tester but will assume it was for 20v AC and up to 7amp and you got nada.

 

The last 18sec video again shows the engine is running fine on the magneto but doing zip for charging.

[Handy Don 13,126]

The VOM AC test between the non-diode lead and the diode lead on the ENGINE SIDE of the diode is the money test. 

Put the VOM in AC mode and be sure it's in the V range not mV.

You should see 14-16 AC volts there when the engine is rev'd up

Edited October 16, 2021 by Handy Don

[TC10284 111]

2 hours ago, Handy Don said:

The starting videos say good battery and normal load as it tries to start.

 

In the 36sec one, 12.56 at idle at the battery seems ok but since it doesn't change upward with higher revs, to 14-ish, there I no charging.

 

The 16 sec video showing 50-70 between one side of the stator and ground is on your VOM's mV (millivolt) scale, not the V scale (usually pressing the Func key several times will let you force the scale from "Auto" to a fixed range--watch the label and the decimal point. But the black lead wasn't grounded?

 

The other videos testing between the two stator lines (and on one, before and after the diode) and not getting any significant voltage says you have a problem with the stator or the wires leading to it.

 

I couldn't see where the red lead was plugged into the amp probe tester but will assume it was for 20v AC and up to 7amp and you got nada.

 

The last 18sec video again shows the engine is running fine on the magneto but doing zip for charging.

 

For the 16 sec video, yeah, I know it's mV and not volt. I just leave it on auto scaling. I'll look into setting that to V instead of auto. Although I am aware of the difference there. The negative lead of the voltmeter is on the negative terminal of the battery. 

 

The voltmeter was set to 20v DC. 

 

[TC10284 111]

2 hours ago, Handy Don said:

The VOM AC test between the non-diode lead and the diode lead on the ENGINE SIDE of the diode is the money test. 

Put the VOM in AC mode and be sure it's in the V range not mV.

You should see 14-16 AC volts there when the engine is rev'd up

 

Alright, so you're saying both leads of the voltmeter into each of the bottom two pins of the 3 pin connector coming off the stator from the engine? Just to be sure I'm clear. I tested that the other day, but I don't really recall the results. I want to say it was 14v AC at WOT when connected to both bottom wires. 

Edited October 17, 2021 by TC10284

[Howie 899]

Ok guys, I just pulled the manual out to check on this. To check the output for AC current you would have to

use a pin and penetrate wire behind the diode. Red lead there and black lead to ground. You do not test both

of them together have to be done separately. The light side will show about 14 volts.  If you are going to test

the output after the doide red to that wire black to the positive side of battery. 

[TC10284 111]

1 minute ago, Howie said:

Ok guys, I just pulled the manual out to check on this. To check the output for AC current you would have to

use a pin and penetrate wire behind the diode. Red lead there and black lead to ground. You do not test both

of them together have to be done separately. The light side will show about 14 volts.  If you are going to test

the output after the doide red to that wire black to the positive side of battery. 

 

I'll give this a try tomorrow and let you know. 

[Handy Don 13,126]

23 minutes ago, Howie said:

Ok guys, I just pulled the manual out to check on this. To check the output for AC current you would have to

use a pin and penetrate wire behind the diode. Red lead there and black lead to ground. You do not test both

of them together have to be done separately. The light side will show about 14 volts.  If you are going to test

the output after the doide red to that wire black to the positive side of battery. 

@TC10284 has the insulation off the wire ahead of the diode so no pin needed.

 

I'd make sure with the ohmmeter that you are clipped to a solid ground, either battery negative or some other spot (ohms between battery negative and your target ground should be zero). (It's likely your battery negative to ground is ok because it is cranking and starting.)

 

Basically you are testing for AC voltage on both sides of the diode to ground/battery negative, and I think that's what I saw in the video (albeit I'm not sure the ground was clipped on for all of them ).

 

BTW, if you do find the 14+ VAC, then you realize that you have a bad connection somewhere starting at that connector!

 

Three other tests. With the engine OFF and connector disconnected:

1. Test for ohms between between the stator wires (on the engine side of the diode for that wire). Good is a very small resistance.

2. Test for ohms between each of the stator wires (on the engine side of the diode for that wire) and ground. Good is infinite resistance.

3. Test across the diode for ohms twice, switching the red and black probes between tests. Good in infinite one way and zero the other way. (Same in both directions means bad diode).

 

Edited October 17, 2021 by Handy Don

[Howie 899]

I missed he had that wire open there. He could check the diode easily then should only flow

one way. Really the manual on this does not give an AC voltage reading on that wire only

the amps reading after the diode. That wire alone is the only one that has anything to do with

the charging.

I guess some of what I am trying to say is that on these dual circuit systems you do use the

two wires to check them like the 12amp or the like.

Edited October 17, 2021 by Howie

[Howie 899]

I Had the wrong engine in my mind, need to read twice I guess. So on a Kohler to check resistance

of the stator, check from behind diode to ground should be 0.7 to 1.3 ohms. Says stator winding is

Ok if checks in this range. If 0 stator winding is shorted. 

For voltage check at 3000 rpm, charging lead to ground should be

28 volts or more using DC voltmeter with charging lead disconnected from battery.

Lighting side check same way, lead to ground Ac voltmeter 15 volts or more.

Engine off resistance lead to ground approximately 0.4 ohms.

 

[TC10284 111]

12 minutes ago, Howie said:

I Had the wrong engine in my mind, need to read twice I guess. So on a Kohler to check resistance

of the stator, check from behind diode to ground should be 0.7 to 1.3 ohms. Says stator winding is

Ok if checks in this range. If 0 stator winding is shorted. 

For voltage check at 3000 rpm, charging lead to ground should be

28 volts or more using DC voltmeter with charging lead disconnected from battery.

Lighting side check same way, lead to ground Ac voltmeter 15 volts or more.

Engine off resistance lead to ground approximately 0.4 ohms.

 

 

I'm guessing in my videos yesterday that I've done most of this, except for checking resistance as you mentioned. I will try to do this today. 

 

I'm going to assume I need to start looking at another stator. 

 

Anyone know what part number I'm looking at? 

I actually have another k301 that I pulled from a different tractor (not wheel horse) that might have it. I'd have to get the engine model # and spec though. I'll get a pic of that today too. 

Edited October 17, 2021 by TC10284

[TC10284 111]

Pics of spare engine. Has same connector. Can't tell the model # off hand. I know I remember seeing it somewhere on there...

https://photos.app.goo.gl/SSKBWV9kZMKhiRb57
 

[TC10284 111]

On 10/17/2021 at 9:09 AM, Howie said:

I Had the wrong engine in my mind, need to read twice I guess. So on a Kohler to check resistance

of the stator, check from behind diode to ground should be 0.7 to 1.3 ohms. Says stator winding is

Ok if checks in this range. If 0 stator winding is shorted. 

For voltage check at 3000 rpm, charging lead to ground should be

28 volts or more using DC voltmeter with charging lead disconnected from battery.

Lighting side check same way, lead to ground Ac voltmeter 15 volts or more.

Engine off resistance lead to ground approximately 0.4 ohms.

 

 

Video test results. Summary - looks like I'm getting appropriate AC voltage for the headlight side (28v WOT), only getting 10v AC from battery charge side (second link) at WOT:

https://photos.app.goo.gl/aR4jUevu2YLvopkR7

 

https://photos.app.goo.gl/bJu1N13YgYJ4m7vbA

[Handy Don 13,126]

8 minutes ago, TC10284 said:

 

Video test results. Summary - looks like I'm getting appropriate AC voltage for the headlight side (28v WOT), only getting 10v AC from battery charge side (second link) at WOT:

https://photos.app.goo.gl/aR4jUevu2YLvopkR7

 

https://photos.app.goo.gl/bJu1N13YgYJ4m7vbA

Glad you got that settled and can move on to resolving it!

Good luck

[TC10284 111]

16 minutes ago, Handy Don said:

Glad you got that settled and can move on to resolving it!

Good luck

 

Update:

I realized I did not test AC voltage BEFORE the diode (not after). BEFORE the diode, I'm getting 15v AC at WOT. 

 

Soo...it looks like my diode is bad(?) and only allowing a max of 10V AC output and 0V DC output. Anyone have a diode part number?

https://photos.app.goo.gl/EkNBJuMFRCqeBxYr5

Edited October 18, 2021 by TC10284

[Handy Don 13,126]

Whoa, that is GOOD news. Diodes are very inexpensive.

 

Did you confirm this by measuring ohms across the diode with the engine connector unconnected and by testing with the red/black probes in both directions? If the reading is the same in both directions it's definitely a bad diode.

 

Any good auto parts store will have a suitable diode.

It should be spec'd for around 30-50volts and 5-8 amps. In bulk, they are about 30¢ but individually you'll pay a $1 or so.

Ideally, it should be soldered in (paying attention to the band marking toward one end of the diode to be in the same direction as the one on the current diode).

I use combo heat shrink solder connectors (also at the auto parts store--for best results, use a heat gun to activate the solder/shrink and not a torch or match!). Since I use a lot of these, I buy an assortment of sizes to keep on hand.

You can wrap electrical tape around the joints and the diode once its connected, but I prefer to use a piece of heat shrink tubing over the entire assembly to reinforce and protect it. Again, I buy shrink tube assortments since I use it frequently.

 

 

[TC10284 111]

1 hour ago, Handy Don said:

Whoa, that is GOOD news. Diodes are very inexpensive.

 

Did you confirm this by measuring ohms across the diode with the engine connector unconnected and by testing with the red/black probes in both directions? If the reading is the same in both directions it's definitely a bad diode.

 

Any good auto parts store will have a suitable diode.

It should be spec'd for around 30-50volts and 5-8 amps. In bulk, they are about 30¢ but individually you'll pay a $1 or so.

Ideally, it should be soldered in (paying attention to the band marking toward one end of the diode to be in the same direction as the one on the current diode).

I use combo heat shrink solder connectors (also at the auto parts store--for best results, use a heat gun to activate the solder/shrink and not a torch or match!). Since I use a lot of these, I buy an assortment of sizes to keep on hand.

You can wrap electrical tape around the joints and the diode once its connected, but I prefer to use a piece of heat shrink tubing over the entire assembly to reinforce and protect it. Again, I buy shrink tube assortments since I use it frequently.

 

 

 

Ohm test of the diode:

https://photos.app.goo.gl/xLAyc2hUPchsHgVbA

[Handy Don 13,126]

3 minutes ago, TC10284 said:

 

Ohm test of the diode:

https://photos.app.goo.gl/xLAyc2hUPchsHgVbA

Not sure how your meter shows "infinity" (is it the "1" in the different ranges?)

If yes, then it looks like your diode is not letting much, if any, current through and is indeed "busted".

[Handy Don 13,126]

With a "no current" diode, there should be no harm if you "sister" it with a known good diode (i.e. jumper the new one in parallel with the existing one keeping black or silver band oriented the same as the one you have--on the side AWAY from the engine it looks like). Then try running the engine and looking for charging.

[TC10284 111]

9 minutes ago, Handy Don said:

Not sure how your meter shows "infinity" (is it the "1" in the different ranges?)

If yes, then it looks like your diode is not letting much, if any, current through and is indeed "busted".

Yes, that is correct sir.