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Issues with pto (solved)

#1

B

Bearrepair

Ok so to start with this i figured the pto switch was bad i took multi meter to it and was not getting complete connectivity through the prongs when pto would be engaged so i ordered a new one. I installed it and still didnt work so i went through checked all the safety switches and all were operating normally so i pulled the new switch and found it had one set of prongs that did not work when engaged so i returned it and got a new one. When i installed the newest switch and attempted this resister or fuse that is connected to the terminals in the wire connector going to the pto burned and split. Now the pto reads 2.9 ohms whitch i thought was good for pto so what are my options anyone have an idea what might have caused this maybe im missing something. I have the 20hp vanguard on this model including in the pictures is the simplicity model designation.20240330_103722.jpg20240330_102947.jpg


#2

ILENGINE

ILENGINE

That is actually a diode to prevent electric feedback and surge voltage when the pto clutch is turned off. they fail on occasion so remove it and see if the clutch works.


#3

B

Bearrepair

ILENGINE said:
That is actually a diode to prevent electric feedback and surge voltage when the pto clutch is turned off. they fail on occasion so remove it and see if the clutch works.
Click to expand...
Yeap that seemed to help! The clutch gave that clunk noise after i removed that part and tested volts going down then put the connector back on gave it a few on and off tests to verify for sure.
Any reason why tho with that part on might it have been an issue?


#4

ILENGINE

ILENGINE

The idea behind the clamping diode is to prevent electrical spikes due to the electric clutch acting like a generator when shutoff. They spike has been know to destroy the EFI ECU's on engines as well as some of Kohler's earlier spark advance systems. They have been know to short out internally causing a short the damaged switches and blows fuses. In some cases should be replaced when damaged but not a part that is really available separately.


#5

StarTech

StarTech

The electrical impulse is call inductive kick back. It also how magneto ignition coils works by collapsing the transformer primary winding magnetic field and generating a large electrical signal in the transformer's secondary. Just in the case of the PTO we are not wanting the induced voltage back feeding into the electrical system. All inductors, solenoids, relays, and transformers produce this kickback. In the case relays and electric when this feed in strong can these to oscillate. I personally have seen relays to chatter the contacts with the damping diodes are not in place. or have failed.


#6

B

Bearrepair

Thanks all for the information. Hopefully i won't have any issues later on with the diod being removed then as you are right ilengine i don't see replacement for it


#7

ILENGINE

ILENGINE

Bearrepair said:
Thanks all for the information. Hopefully i won't have any issues later on with the diod being removed then as you are right ilengine i don't see replacement for it
Click to expand...
Here is a link to the Kohler pto clamping diode kit



#8

B

bertsmobile1

The diode should have some numbers on it that will identify it
Any reasonable electrical component store will be able to identify it and supply a replacement
Do not be surprised if you have to buy a pack of 10 or 20
When you remove it , cut one wire long and the other short so you remember which way it went in
They are directional so backwards will give you grief
Stick the remainders on Evilpay for double what you paid for them.


#9

StarTech

StarTech

I was going to suggest that the OP if the numbers were still readable to post them. Usually a couple fifty terminals and the diode is all that is needed to be replaced. And take a picture of the current layout would help too.

Plus it help us that does the component level repairs to know diode was used. Personally I don't see a reason a for shop to have to pay 3X or more for the parts and then have to charge the customer even more.


#10

B

Bearrepair

StarTech said:
I was going to suggest that the OP if the numbers were still readable to post them. Usually a couple fifty terminals and the diode is all that is needed to be replaced. And take a picture of the current layout would help too.

Plus it help us that does the component level repairs to know diode was used. Personally I don't see a reason a for shop to have to pay 3X or more for the parts and then have to charge the customer even more.
Click to expand...
Unfortunately the crack right down the middle burned any identifying numbers i could make out so i have no idea what it was i could install another and Solder it in no problem . I could not find it on parts lists tho when looking


#11

ILENGINE

ILENGINE

Bearrepair said:
Does that have the same type

Unfortunately the crack right down the middle burned any identifying numbers i could make out so i have no idea what it was i could install another and Solder it in no problem . I could not find it on parts lists tho when looking
Click to expand...
That is the diode that we had to install on mowers when doing the DSAM to DSAI conversion to prevent damaging the ignition system when the pto clutch was shutoff. May not be an exact replacement but was designed to do the same thing that the one in your wiring harness was designed to do.


#12

B

Bearrepair

Hey all i was wrong i can make out the diode numbers i guess i looked at the wrong side when i clipped it off its t6a60

Attachments





#13

StarTech

StarTech

TAITRON T6A60L 6 amp 600V with a surge current rating of 400 amps.

T6A60L SPEC SHEET

Suggested US replacement part at a cost of 0.39 USD ea plus shipping.
1711920945066.png


#14

B

Bearrepair

StarTech said:
TAITRON T6A60L 6 amp 600V with a surge current rating of 400 amps.

T6A60L SPEC SHEET

Suggested US replacement part at a cost of 0.39 USD ea plus shipping.
View attachment 68185
Click to expand...
Hey man thats great thanks !


#15

B

Bearrepair

ILENGINE said:
That is the diode that we had to install on mowers when doing the DSAM to DSAI conversion to prevent damaging the ignition system when the pto clutch was shutoff. May not be an exact replacement but was designed to do the same thing that the one in your wiring harness was designed to do.
Click to expand...
Yeah i was starting to lean that way till the diod replacement was shown here its a much easier fix if i have something that i couldnt repair as easy as just popping on another diod!


#16

H

hlw49

You can buy a jumper with the diode in it. Dixie Chopper makes one I know. Don't have access to the part no. now but can get ti.


#17

StarTech

StarTech

What Bearrepair just did by posting the diode pn is to help all the professional shops here to help lower the repair cost for our customers while we make a profit on repairs. Simplicity was just wanting us to buy an expensive wiring harness to replace the diode.

Yes DIYers don't have the same access as we do but for it is a simple matter of buying the after market diode and a couple Aptiv terminals which in when we buy in bulk only cost us a couple dollars which mean we could the components for $5 (example) vs a $100 wiring or the $17 replacement that IL linked.

Personally I appreciate that Bearrepair took the time to post the component numbers for me to look up.

Now all I got to do here is to put these diodes on my next Mouser order.


#18

B

bertsmobile1

Soldering the replacement will do fine.
Usually they are just crimped together with the wire at the terminals ( cheap ) before the terminals are inserted into the plug
If you have the terminals , crimper & extraction tool it is a 3 minute job
Just remember they are polarity sensitive as is a lot of the clutches .


#19

StarTech

StarTech

Yes the diodes are usually unidirectional. This is why they are used to convert AC to DC. They are also call rectifiers.
There are also special diodes for other purposes.

Note the band is on the Cathode side. In this application the Cathode goes to the +12v side and Anode side goes to ground.
1711972066181.png
Anode Cathode


#20

B

Bearrepair

Thanks for all the feedback this has been a great learning experience for me! I already ordered the diods and will have a couple spares just in case for later. I hope to have it ready for spring as im a hobby mechanic and make side money foxing things and its been fun and rewarding! But ive never asked for help until this issue most things i was able to figure out but we are only human and sometimes need the knowledge of others to continue forward!


#21

B

bertsmobile1

Bearrepair said:
Thanks for all the feedback this has been a great learning experience for me! I already ordered the diods and will have a couple spares just in case for later. I hope to have it ready for spring as im a hobby mechanic and make side money foxing things and its been fun and rewarding! But ive never asked for help until this issue most things i was able to figure out but we are only human and sometimes need the knowledge of others to continue forward!
Click to expand...
That is why we are here to help & also learn.
Like Star I have added some to my next electrical parts order .
I found one listed for Cub and it was $ 42 wholesale so $ 5 worth is a good investment if I can charge $ 20 and save the customer $ 20 .
Otherwise you are looking at a full loom and that is in the hundreds .


#22

C

closecut

A 1N4007 diode will wok just fine.It has a 1000volt peak reverse voltage.Here is a link to diodes on Amazon.Cheap as dirt.The negative end has a line on it,put this to the positive end of the solenoid..it should only conduct when the reverse spike arrives,hence the reverse connection.You may have to purchase more than you want,but they are cheap.I have used these diodes on golf carts,mowers,tractors,and lots of other machinery for the same purpose.


#23

StarTech

StarTech

closecut said:
A 1N4007 diode will wok just fine.It has a 1000volt peak reverse voltage.Here is a link to diodes on Amazon.Cheap as dirt.The negative end has a line on it,put this to the positive end of the solenoid..it should only conduct when the reverse spike arrives,hence the reverse connection.You may have to purchase more than you want,but they are cheap.I have used these diodes on golf carts,mowers,tractors,and lots of other machinery for the same purpose.
Click to expand...
So you saying a 1 amp, 30 surge amp diode replaces a 6 amp, 400 surge amp diode?
1712405205115.png

OEM used a 6amp, 400a surge for a reason.


#24

F

Freddie21

The white ring on the diode is the cathode, or negative end. As far as the replacement goes, if wires are attached and you can't see the ring, the black wire should be the cathode. The red wire is the anode or positive end. If you can get the raw diode by itself, it will be much cheaper. Most of the time, you can go one of equal physical size, or larger, if the specs are not known.


#25

C

closecut

StarTech said:
So you saying a 1 amp, 30 surge amp diode replaces a 6 amp, 400 surge amp diode?
View attachment 68233

OEM used a 6amp, 400a surge for a reason.
Click to expand...
Yes.The diode I recommend is better than the oem.
The oem is the minimum to do the job, and the cheapest.It also allows them to sell more parts.Look at the price for the replacement parts that cost only pennies each.Lots of companies making lots of money due to the dumbing down of society.Replace a wiring harness because of one bad diode?Ba! Humbug!
It is the voltage that kills a diode.The pulse does not last long enough to create the wattage needed to blow the diode.I have used this replacement for many years with no repeat failures.Take it for what it is worth.


#26

StarTech

StarTech

closecut said:
Yes.The diode I recommend is better than the oem.
The oem is the minimum to do the job, and the cheapest.It also allows them to sell more parts.Look at the price for the replacement parts that cost only pennies each.Lots of companies making lots of money due to the dumbing down of society.Replace a wiring harness because of one bad diode?Ba! Humbug!
It is the voltage that kills a diode.The pulse does not last long enough to create the wattage needed to blow the diode.I have used this replacement for many years with no repeat failures.Take it for what it is worth.
Click to expand...
Something just not right about replacing a 400a surge with a 30a surge rated diode. Yes the voltage rating can be higher but doesn't affect the amp rating.

Besides the one I recommended is a 1000V unit which would make a better replacement than the 1N4007.
1712491266850.png


#27

StarTech

StarTech

Freddie21 said:
The white ring on the diode is the cathode, or negative end. As far as the replacement goes, if wires are attached and you can't see the ring, the black wire should be the cathode. The red wire is the anode or positive end. If you can get the raw diode by itself, it will be much cheaper. Most of the time, you can go one of equal physical size, or larger, if the specs are not known.
Click to expand...
If you had looked at the OP wiring you would seen that he doesn't have a red wire at the PTO. Instead he has a black wire with white tracer for positive side and a black wire for the negative side.


#28

C

closecut

1712492461377.gif
StarTech said:
Something just not right about replacing a 400a surge with a 30a surge rated diode. Yes the voltage rating can be higher but doesn't affect the amp rating.
Click to expand...


#29

C

closecut

closecut said:
View attachment 68249
Click to expand...
1N400X DiodeReverse Voltage
1N400150 V
1N4002100 V
1N4003200 V
1N4004400 V
1N4005600 V
1N4006800 V
1N40071000 V


#30

C

closecut

The 700 volts is the maximum constant supply voltage that it can handle.
The PRV is the reverse voltage it can handle.The reverse spike is a very short,sharp, low wattage,high voltage surge.Look at the spike on an oscilloscope,you will see what I mean.You do have an oscilloscope,don't you?
My experience(over 50 years in electronics) has led me to this replacement over the OEM standard-designed-to fail,sell more parts replacement.I have seen NO REPEAT FAILURES.If the OEM was 1N4007 it would never fail at all,unless a case of direct lightning strike nearby, caused by an induced EMP from the strike.(Electro Magnetic Pulse). The 1N4007 is rated for 1000volts PRV.


#31

StarTech

StarTech

Are you saying that PTO is going to supply over 700 RMS (AC) voltage constantly? What the PTO is going to produce is a peak DC surge voltage and current at same time as the magnetic field collapses. Both diodes can handle the 1000 PIV inverse voltage. The diode is use to short circuit the inverse DC voltage which would cause a high current in the PTO clutch field clamping any induced voltage and current. Beside the repetitive peak rating is 989.8v (700 VRMS); Pretty darn close to 1000V repetitive voltage.

Beside the 1N4007 has the same RMS rating.
1712495637033.png

Now AC and DC can be on the circuit as the same time as I am currently running a system here that does that 24/7. Just requires a DC blocking circuit prevent the DC on the AC only circuit.


#32

C

closecut

StarTech said:
Are you saying that PTO is going to supply over 700 RMS (AC) voltage constantly? What the PTO is going to produce is a peak DC surge voltage and current at same time as the magnetic field collapses. Both diodes can handle the 1000 PIV inverse voltage. The diode is use to short circuit the inverse DC voltage which would cause a high current in the PTO clutch field clamping any induced voltage and current. Beside the repetitive peak rating is 989.8v (700 VRMS); Pretty darn close to 1000V repetitive voltage.

Beside the 1N4007 has the same RMS rating.
View attachment 68250

Now AC and DC can be on the circuit as the same time as I am currently running a system here that does that 24/7. Just requires a DC blocking circuit prevent the DC on the AC only circuit.
Click to expand...
That is not what I am saying.Read my reply carefully.The flyback(reverse voltage) is the most important in this case.
The spike can puncture the P/N junction long time before the current can affect it. The applied constant voltage is the max it can withstand,not that it is the applied voltage in this case.
You are preaching to the choir about applications,and you do not fully understand the specification meanings.Do your homework and reply ..or not.I am not going to tutor you in things you should already know.(A capacitor can also block DC voltage and is used in many applications,such as audio,video,etc.but with different circuit requirements.)A capacitor can also direct ac to ground,or another section,depending on frequency, of the circuit as well,while passing the AC signal through.


#33

StarTech

StarTech

Oh just forget it. The specs are the same except the 8.3 ms surge current ratings and package design. That is if you bother to look at both spec charts.


#34

C

closecut

The proof is in the pudding as they say.No repeat failures with the 1n4007.When I was 10 years old,I was building cat whisker radios,(1960's) then vacuum tube radios,then transistors came along,solid state radios,then binary computers and I learned binary,boolean algebra, various programming languages starting with low level programming,where you had to manipulate the registers on machine level using binary or octal or hexadecimal, Basic,C,C+C++,Fortran,Cobol,and UNIX and other proprietary languages,like Ftran.Along the way,I worked as a mechanic for a dealer ship,went to factory schools,built a race car,I know what works and lasts and what doesn't work or last.
Minimum specs that will live through the warranty period is the mantra of modern business.I see it across all sectors,appliances,cars,electronics.
Look around and you will see what I mean.
Exit 0
Adious Amigo


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