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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 27042
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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The interlock module is sending battery voltage to both PTO

Customer Question

The interlock module is sending battery voltage to both PTO clutch wire leads.
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.

Check # ***** diode, Diode is a one way electrical check valve.

Expert:  Curtis B. replied 1 year ago.

https://polr.partstree.com/v1/iplimage.php?ir=YTozOntzOjY6ImxpbmVJZCI7czoxMDoic2ltcGxpY2l0eSI7czo5OiJpbWFnZVBhdGgiO3M6Mjg6ImFXMWhaMlZ6WERBeFhERTVYREV4TURJd05EWTAiO3M6Nzoib3B0aW9ucyI7YToxOntzOjU6IndpZHRoIjtpOjEwMDA7fX0

Expert:  Curtis B. replied 1 year ago.

https://www.partstree.com/parts/simplicity/mowers-lawn-garden-tractor/1691528-simplicity-sunstar-garden-tractor-18hp/main-wiring-harness-group-all-mfg-nos-except-1691017-1691018/

Expert:  Curtis B. replied 1 year ago.

You can be getting feedback through the diode.

Expert:  Curtis B. replied 1 year ago.

The clutch has to have one side grounded,and you have lost the ground side!

Expert:  Curtis B. replied 1 year ago.

I assume your problem is the clutch won't engage.

Customer: replied 1 year ago.
Thank You for your answers! Your assumption is correct, I grounded one clutch lead to the frame and mowed for ½ - 3/4 hour and the clutch worked great! Is the #31 diode you make reference to located in the interlock module? If so, you want me to renew the interlock module?
Dan
Customer: replied 1 year ago.
By looking at the wiring parts on the diagram I noticed what the diode is and what it plugs into. When I got the tractor I noticed that the diode (at the time I didn't know that it was a diode) was unplugged from the connector and not knowing if it should be connected or not I plugged it into the connector. But the PTO clutch did not engage and later I unplugged the diode from the connector. Now I see that the #31 is the part reference in the wiring diagram for the diode. I thought the problem might be in the interlock module so I was going to renew it but the price of the diode ($15.26) is a whole lot less than the interlock module ($154.17).
Thank You very much!!!!
Expert:  Curtis B. replied 1 year ago.

Thank you!

Customer: replied 1 year ago.
I like your responds about the diode very much, I ordered the part and will install it quickly and let you know if it solved the problem.
Thank You,
p.s. FYI I order my parts from Jack's Small Engine Parts and I have for many years. I have had very quick shipping and find almost all of the parts I've compared with Parts Tree cost less.
Customer: replied 1 year ago.
Diode arrived today, installed it and tested for ground to PTO clutch. Unfortunately the output from the interlock module is still sending battery voltage to the PTO clutch instead of the needed ground. I was so hopeful the problem would be the diode. I'm beginning to tear my hair out on this job. HELP!
Expert:  Curtis B. replied 1 year ago.

Is diode in the circuit and is it installed correctly?

Expert:  Curtis B. replied 1 year ago.

It only blocks current in one direction.

Customer: replied 1 year ago.
Yup, I even put dielectric grease on both contacts. I checked the old one and in one direction I had battery voltage, turning it around and testing there was very minimal voltage going through. I should have checked the old one before I ordered a new one.
Expert:  Curtis B. replied 1 year ago.

You know the clutch will work if you ground one side, what happens if you just leave it like that?

Customer: replied 1 year ago.
I've done that and mowed with the tractor for ½-3/4 hour and the clutch worked fine. The problem of leaving it that way is that the mower doesn't stop if the driver gets off the seat. Being that two (2) handicapped men drive it grounding the PTO clutch to the frame is not an option. I'm still wondering if the problem is in the 'interlock module' as when the problem first started was when the engine warmed up. The operator could not re-engage the PTO clutch after the engine warmed up. The operator would wait for awhile then restart the tractor, engage the PTO clutch and mow until he shut off the mower and would try to re-engage the PTO clutch. Something to do with engaging the PTO clutch after the engine warmed up is the problem because when a component got hot it wouldn't engage the PTO clutch..
Expert:  Curtis B. replied 1 year ago.

Interlock module will do it. But you know the price!

Customer: replied 1 year ago.
I did find something while I was doing some testing today. With the ignition switch OFF and the PTO switch ON the interlock module is sending ground to the PTO clutch. With the ignition switch ON and the PTO switch ON the interlock module is sending battery voltage to the PTO clutch. This seems backward to me. With the ignition switch ON the interlock is sending battery voltage to the other lead to the PTO clutch. Something is very wrong.
Expert:  Curtis B. replied 1 year ago.

!! still looks like the module.

Customer: replied 1 year ago.
OMG, you work around the clock? I did not expect an answer at 8:50 on a Saturday night! You are very devoted to your job. I'm thinking that heat could affect the interlock module and eventually burned something out so that the module is now bad all of the time not just when it was hot. Do you concur with that analogy? If so I'll check with my customer to see if he wants to spend $156.00 on his tractor.
Thank You ever so much.
Expert:  Curtis B. replied 1 year ago.

I don't see how it could be anything else!

Expert:  Curtis B. replied 1 year ago.

If I'm in front of tv, I have my laptop!

Customer: replied 1 year ago.
I don’t seem to be able to contact the customer to find out if he wants to spend $156 for the interlock module. I am already not charging him for a complete new PTO clutch, a oil pressure sender and the diode which did not solve the problem. I hate to get stuck with a $156 part that also may not solve the problem.
Dan
Expert:  Curtis B. replied 1 year ago.

!! I know , I have been there! Let me know.

Customer: replied 1 year ago.
I received permission to order and install the interlock module. I'm holding off to be sure the module fixes the problem.
Expert:  Curtis B. replied 1 year ago.

OK, thanks.

Customer: replied 1 year ago.
The interlock module is on back order, ruffly another week. I do have another concern that I hope you can help me with. The customer bought a new PTO engage switch thinking that's what was wrong with it and installed it. Of course that didn't fix the problem but he told me that one of the connectors to the switch might not be installed on the switch correctly. One of the connectors is a three plug connector and can be installed only one way. The other plug is a two plug connector and can be installed two ways. One of the plugs on the connector has two wires going into one plug, the colors of the two wires are blue and white. I need to know if the two wire plug goes toward the toggle on the switch or away from the toggle. I'm worried that if that plug isn't put on the switch correctly the new interlock module may be destroyed and I can't stand to be stuck with any more parts! I did ask another technician from 'justanswer.com' but he never followed through to answer my question.
Thank You,
Expert:  Curtis B. replied 1 year ago.

http://www.partstree.com/parts/simplicity/mowers-lawn-garden-tractor/1691528-simplicity-sunstar-garden-tractor-18hp/main-wiring-harness-group-all-mfg-nos-except-1691017-1691018/

Customer: replied 1 year ago.
This is for parts, I need a diagram that shows all wire colors. Especially the wires that plug into the PTO engagement switch. This shows some colors but not all wire colors.
Thank You,
Expert:  Curtis B. replied 1 year ago.

That is all I have. I will opt out. Maybe someone else can help.