Walk behind unit electrical problem

[Luffydog]

Because the clutch is dc not ac. Like everyone has said put it back like new and give it a go and see what happens. If things doesn't work correctly as far as the safety then one of the safety's are bad and yes that might include the pto switch being bad. Meaning if your mower starts and run correctly then after heating up and you decide to stop and get a drink or get off the mower for a pick up and it quits meaning pto switch doesn't realize that the blades are off and kills the mower. If you stop you turn off the engine and rest then you go back out and the mower doesn't start although the switch is it doesn't realize the clutch is off because the switch has failed if all the others are working correctly and hooked up like they should be. Yes there is a test that can be done for most that had the safety interlock module. But really nobody can really help you if you won't listen to what is going on with the safety switches and with the life safety and personal injury. Most here are pros and dealers who deal with theses issues on a daily basis and take great pride to help others who have issues. We don't step out of bounds!!!! Hands down and hats off to Bert.

 

[Richie F]

I was going to leave this alone because of the belief that if you can not work out how to bypass things that are there for your own safety then you should leave them alone.
If understanding how they work is beyond you mental capacity then operating the machine safely is probably beyond your mental capacity as well.
None of them will stop you using the machine to it's full capacity if they are working and there is no real reason to bypass them.
The pto switch should be shown in the wiring diagram.
They are generally shown turned off so you continuity test them off and then on then go back to the wiring diagram.
It is a switch so some pairs will be open & some will be closed depending upon which position the switch is in and I have already told you it switches left to right and if it is a 3 row switch the middle ones are all connected together.

As for the operator presence switch plug, that is common now days to prevent the red neck, brain dead simply unplugging one then getting injured.
The reason is because some idiot moron bastards pulled them out , got hurt, then got massive damages payments by convincing a judge that it is possible for the plug to "fall out " without the operator knowing it.
So a simple plug that was cheap & easily available became very expensive & very hard to get one
Some companies have gone the other way by making safety switch a normally closed switch.

If you thought that a Scag employee or dealer was going to tell some one over the phone how to bypass the safety features, many of which are a legal requirement, then you must be incapable of reason.
The factory fits safety equipment then I tell you have to defeat it, you get hurt then I have left myself open to a massive law suit.

So naturally they will not tell you how to do it, not unless they are barking mad.
They might have told you how to test the various parts are working but that would be the limit of what a reasonable person would expect from them.

And you are yet to divulge why it is vitally important that your friend gets the safety switches bypassed on his mower.,
And have another thought, does his wife & children love you to the point that if he looses a hand or foot using the mower that you made "legally unsafe to operate", none of them will yield to the ambulance chasing lawers promising them they can get millions from you & Scag in compensation ?

How strong do you think your friendship is ?
lots of folks in the poor house because a close & trusted friend was not quite as close when an oppertunity to make a big amount of money presented itself.

First off I am not stupid and have been in the automotive field for over 50 years.
Second I only called SCAG to ask the function of the switches, the conversation drifted as we talked. Their wiring schematic does not explain this like other schematics I have looked at.
Third I agree that all switches should in place.
Forth I feel you should get off your high horse and just stay within my first post question. Don't start drow beating someone you don't even know.

 

[Richie F]

Because the clutch is dc not ac. Like everyone has said put it back like new and give it a go and see what happens. If things doesn't work correctly as far as the safety then one of the safety's are bad and yes that might include the pto switch being bad. Meaning if your mower starts and run correctly then after heating up and you decide to stop and get a drink or get off the mower for a pick up and it quits meaning pto switch doesn't realize that the blades are off and kills the mower. If you stop you turn off the engine and rest then you go back out and the mower doesn't start although the switch is it doesn't realize the clutch is off because the switch has failed if all the others are working correctly and hooked up like they should be. Yes there is a test that can be done for most that had the safety interlock module. But really nobody can really help you if you won't listen to what is going on with the safety switches and with the life safety and personal injury. Most here are pros and dealers who deal with theses issues on a daily basis and take great pride to help others who have issues. We don't step out of bounds!!!! Hands down and hats off to Bert.

"Because the clutch is dc not ac. "
That's what I said to SCAG. The person said the rectifier is AC not DC. So how can it being AC, power the clutch, it can't. A rectifier is the part that changes AC to DC. You have a single phase stator that is AC.
Again I agree with putting everything back, but just for general knowledge I want to know the correct function of the switches so when I test them I can say this switch is good I'll now hook it up.

 

[tom3]

Might consider the person you talked to at Scag probably doesn't know a wrench from a screwdriver. When you ask a question the answer pops up on a screen. The term rectifier probably comes up with a part number and price so he's winging it, has no clue.

 

[Richie F]

Might consider the person you talked to at Scag probably doesn't know a wrench from a screwdriver. When you ask a question the answer pops up on a screen. The term rectifier probably comes up with a part number and price so he's winging it, has no clue.

Thank you. That's what I was implying about the conversation with the person.

 

[NorthBama]

Most pto switches have 3 terminals right to left and marked ( NC) normally closed (NO) normally open and (COM) for common to both normally open and normally closed. some have one row that may have only 2 terminals

 

[bertsmobile1]

If you can not work out this wiring diagram then I can not be of any help to you.

https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/scag/walk-behinds/sw36a-14fs-walk-behind-s-n-j6100001-j6199999/sw-electrical-schematic-recoil-start

As previously mentioned if some one needs instructions to the level of "Join the pink wire to the green wire and cut the blue one just past the yellow wire junction" , they should not be touching the wiring.

The wiring diagram is not hard to find and it has the PTO switch connections on it.
It is a standard 3 row 8 pin plug. The terminals closest to the dash are not used because they are the pass through terminals for the starter motor that you do not have
I really can not see what your problem is , the wiring diagram is clear as crystal.

 

[Richie F]

Most pto switches have 3 terminals right to left and marked ( NC) normally closed (NO) normally open and (COM) for common to both normally open and normally closed. some have one row that may have only 2 terminalsView attachment 45167

Thank you for this information.
I do understand what NO, NC and COM means.
Have looked on YouTube to get a background on how this switch functions on a lawn mower that uses it.

 

[bertsmobile1]

Here is the wiring for this machine.

https://www.partstree.com/models/sw...kawasaki-sn-j6100001-j6199999/wire-harness-9/

Going to contact SCAG at 1-800-937-7279 to ask them what the switch function is in the circuit.
Are they all NO (Normally Open) or are some NC (Normally Closed).
That will help in tracing out the ground circuit.

NO THIS IS NOT A WIRING DIAGRAM IT IS A HARNESS LAY OUT DIAGRAM>
IF YOU HAD PUT THIS LINK UP FROM THE GET GO SOME ONE PROBABLY WOULD HAVE NOTICED YOU WERE LOOKING AT THE WRONG DIAGRAM

This is what a wiring diagram looks like
https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/scag/walk-behinds/sw36a-14fs-walk-behind-s-n-j6100001-j6199999/sw-electrical-schematic-recoil-start

 

[Richie F]

If you can not work out this wiring diagram then I can not be of any help to you.
As previously mentioned if some one needs instructions to the level of "Join the pink wire to the green wire and cut the blue one just past the yellow wire junction" , they should not be touching the wiring.
The wiring diagram is not hard to find and it has the PTO switch connections on it.
I can not see what your problem is
https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/scag/walk-behinds/sw36a-14fs-walk-behind-s-n-j6100001-j6199999/sw-electrical-schematic-recoil-start

Bert have you not read my first post ?
I have the wiring schematic already.
What I was hoping for when I started this thread was someone who had this problem and would have told me.
Could have saved a few steps.
You keep talking to me like I'm an idiot.
No, I have not bought a highlighter marker yet to backtrack the circuit. Forgive me your lordship.
I don't need "Join the pink wire to the green wire and cut the blue one just past the yellow wire junction"
When I find the functions of the safety switches it will be very easy to trace the circuits.
I will have time today to compare the problem machine to my friends other 3 SCAG walk behind units.
There are one other 36" and two 48".
Thanks for your input.