STX38 electrical issues

BlazNT

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I tested the PTO switch and it is good. The mower was running when the old PTO clutch went out.

How did you test the PTO switch? What is the engine model number?
 

tim2

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To test the switch I loaded themower and took it to a repair shop and had them test it. The engine model number is CV13S. I really need to know where the realays and fusabily links, and fuses might be.
 

bertsmobile1

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I poked around for a little while on it yesterday and came up with nothing new. I will check your last tip today, I have an appointment this morning so it will be later today. I have not seen any signs of relays, it appears everything is just straight wired with no relays, fuses or fusible links. Anyone have a wiring diagram for this STX38 or ideas where the relays and fusible links are?
Bert, the purple wire from the solenoid goes directly to the PTO clutch and the other wire goes back to the PTO switch. I will post back what I find today.

No it does not not.
It should go to a safety switch and that is usually the brake as that in under the mower just near the solenoid.
From there to the PTO switch and from there to the key switch.

The starter solenoid is not connected to the clutch or the engine would crank whenever you turned the blades on.


The PTO clutch wires are Blue + 12V and black ( earth )
 

BlazNT

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Try unplugging the lighting circuit from the PTO switch and then report back.
 

tim2

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Okay, I chased these wires yesterday and this is what ids on this mower. The purple wire leaves the solenoid and goes to the PTO clutch, there is a black wire leaving the PTO and it goes to the switch to engage the blades. That is how it was wired when the guy pushed it up my driveway. There is no wiring from the PTO to the lighting system. I have NOT FOUND a relay, fuse or fusible link yet. I am at a total loss with this no power to the starter.
 

bertsmobile1

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Well no wonder it did not go.

There should be a blue wire and a black wire that goes from the PTO switch to the clutch.
Where they go through the mower floor there should be 2 wire plug so you can change the clutch.

The starter solenoid and the PTO clutch can not be on the same circuit because they are mutually exclusive.
You can not start the mower with the blades engagd and the blades can not engage while you are starting the mower.

Now this is going to be a PIB type job but as some one has been in there making a mess out of things you now have to set it right.

Nice thing about JD is their wiring colour scheme is farily well consistant.
We will start everything from the key ( start ) switch because this will keep things simple as possible.
Remove the plate with the start switch & pto switch on it, it should have enough cable to pull up clear of the fender.
Flip it over and test for 12 V at the red wire and ground on the black wire.
If you do not have 12V at the red wire , nothing will work
Look closely at the back of the switch you will see the following
G - Ground wire,Black direct contact to ground
M - Magneto kill wire , White can be single double or tripple , connects to the magneto and the safety cut out switches. Kills the spart to turn off the engine , connects to the black wire with the ignition off.
B - Battery wire, Red, 12V connects to the + on the battery or the battery lead on the solenoid. This wire should have the fuse on it.
A - Accesory ( run) wire, Yellow , goes to the carb solenoid ( if you have one ) and the light switch ( if you have one )
S - Start wire , purple, usually goes to the PTO switch and becomes purple + white ( or + yellow ) then goes to the brake or neutral switch and becomes full purple again hence on to the starter solenoid.

Connections go like this
OFF G + M
ON B + A
START B + A + S

So check the ignition switch and report back
If your brain is not fried you can try tracing the purple wire. It may got to a few other things and usually will change colour every time it goes through a switch so purple + white, purple + yellow , purple + black etc etc etc.
Even worse it can go purple then purple + trace then revert to purple then purple + trace so just because a purple goes in and a purple come out it does not mean it has not been through a few switches.
 

tim2

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Well I have not fried my brain. I checked the switch as suggested and everything checks out. I am still baffled by the purple wire going from the solenoid to the PTO Clutch. When I started trouble shooting the mower you could here the solenoid click every time you turned the key but the motor would not turn over. I pulled the spark plug and tried the key again, solenoid clicked and motor did not turn over. I removed the plastic cover on top of the motor and tried to turn it over first by han then with a wrench and could not move it. I then looked underneath and found the PTO clutch burned out. I removed the clutch, both wires in one plastic housing(one wire is purple). Installed the new clutch plugged the wires into it. Turn the key and nothing at all not eventhe clicking noise from the solenoid. It looks like it is going to need to be taken to a shop. I would really like to see a wiring diagram for this model engine CV13S. Hopefully someone has it and can post a copy of it or a link to one.
 

tim2

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I thatnkyou for the diagrams. Now does the guy want to pay $200 for a new wiring harness or not?
 
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