PTO switch wiring

[Zipper89]

I was given an MTD pro 1852 that was only running on one cylinder with the blades working months ago. I fixed the engine issue but now the blades won’t come on. I’m seeing if anyone knows how the PTO switch gets 12v because I cannot find it anywhere. Also the black and white wires from the clutch and dangling under the key with nowhere to plug them in. I can put 12V directly to the white wire and get the clutch to engage but the engine shuts off. It seems like a safety switch thing.

The red wire coming into the key switch has constant 12v. The only wire the gets 12v with key on is a thicker yellow wire that goes to the starter. I assumed 12v would go to the PTO switch from the key but there is none. If anyone has any idea about wiring the PTO switch or some schematic I would greatly appreciate it.

 

[Rivets]

Please provide us with all unit and engine numbers. Without them we’re only guessing as how to tell you to proceed.

 

[Zipper89]

Please provide us with all unit and engine numbers. Without them we’re only guessing as how to tell you to proceed.

I’ll look again, but I’m pretty sure the model/serial number tag is missing from the mower. I see a spot where the was a tag before.

 

[StarTech]

If this is a 1852H 55AF3C5T195 52" Hydro walk behind

The L is the accessories terminal IE PTO terminal. The terminal with the S is the starter solenoid terminal

As an electrical schematic this a major problem I have MTD as they rarely ever publish one.

 

[Zipper89]

If this is a 1852H 55AF3C5T195 52" Hydro walk behind

The L is the accessories terminal IE PTO terminal. The terminal with the S is the starter solenoid terminal
View attachment 72762View attachment 72763
As an electrical schematic this a major problem I have MTD as they rarely ever publish one.

Yes this is exactly what I was looking for. I’ll see if the L terminal is getting 12V. And yes it is a 52” hydro walk behind.

 

[Zipper89]

If this is a 1852H 55AF3C5T195 52" Hydro walk behind

The L is the accessories terminal IE PTO terminal. The terminal with the S is the starter solenoid terminal
View attachment 72762View attachment 72763
As an electrical schematic this a major problem I have MTD as they rarely ever publish one.

So the L terminal is the yellow wire I was talking about. It does get 12V when key is on, but it leads to a connector which splits off to the starter and what I think is a voltage regulator on the side of one of the cylinders. I can’t find any wires that bring that power back up to the PTO switch.

So I guess this means the key switch is working properly if the L terminal is the only one that needs 12V output when key is on.

 

[slomo]

See lots of raw uninsulated wires, corrosion and general filth. Marine grade heat shrink, plastic loom and some Tesa tape to the rescue.

 

[StarTech]

And PTO switch make/break table. Colors just indicates the different poles.

 

[Zipper89]

And PTO switch make/break table. Colors just indicates the different poles.
View attachment 72765

I tested the continuity for both positions and everything tested fine. The part I’m hung up on is this:

There is a red wire in pin C2 or top middle that leads out to nowhere. I’ll attach a picture of the connector it goes to, but there is nowhere for this connector to plug in. Adjacent to the red wire from that connector is an orange wire that goes to a 30amp fuse, then to the PTO switch top right, then to the hour meter. I’d assume the red wire is supposed to be the 12v in to the PTO switch but I’m not sure.

 

[Zipper89]

If it helps anyone in the future I fixed it. I put 12v from the L pin (yellow wire) to the red wire (top middle pin) going to the PTO switch. Then I connected the white wire that comes from the clutch to the orange wire (top right pin). Not sure how the last owner had it working but he said the blades worked just fine. Thank you everyone for your help.