Dk40se pto switch

[Kodiak45]

On my recently purchased used 2009 dk40se, I noticed the pto isn't engaging. The switch light comes on and I've tried fooling with the manual / auto switch and it does light up also but the shaft does not spin nor do I hear anything different when I turn the switch on. I didn't have time to investigate tonight, but I'll be back to the farm on Friday or Saturday. Where should I start this diagnosis? I suppose the light on the switch doesn't doesn't mean much besides it has power, but it doesn't mean it's working to send power to the relay/solenoid...right? My electrical knowledge is limited, but I'm hoping I'm on the right track. Thoughts?

 

[Kodiak45]

Is there an electrical wiring diagram available anywhere?

 

[Harry in Ky]

Can't say for sure with your particular tractor brand/model, but MOST tractors of this size/type use a fairly common approach to controlling the PTO. There is often a solenoid valve incorporated into a somewhat square shaped valve body, usually on the right side of the trans case somewhere below the area where your right foot would be while operating. This valve body will have multiple hydraulic lines leading in and out along with some plugs and fittings. Somewhere on there it will have a 12v solenoid coil probably an inch or so in diameter and an inch/inch and a half tall with one or possibly two wires attached depending on whether it's internally or externally grounded.
12 volts supplied to this coil will engage the PTO clutch. The switch circuits can vary somewhat from tractor to tractor, often incorporating a starter interrupt feature, pilot light, maybe an auto mode to involve the three point lift with even more switches to interrupt the circuit if the lift is raised to a certain point then re engage when lowered. The wiring to the various components is often routed through some vulnerable places.
I would start by locating the coil, and testing for 12v at that point with switches in "on" position. If voltage is present, then suspect/test/replace the coil. I have seen them fail. If all that checks out, you have bigger issues than just an electrical problem.

 

[Kodiak45]

Thanks for the help. I have realized first hand and also read that these tractors have electrical issues, although minor, can be annoying. I'll look for the solenoid and confirm voltage and go from there. Thanks again

 

[ritcheyvs]

You need to locate the wiring and connectors from the PTO switch to the solenoid. First, rule out damaged wires and corroded/dirty connections. Then get a volt meter and check if power is getting to the solenoid. If not, trace the electrical path to find where the current is interrupted, You'll also need a schematic, which is in the service manual. I highly recommend buying a paper service manual from a dealer, as a matter of paying your way. In the meantime, it is possible to download a service manual. I believe the SE models are the same as the EX models. You can try swapping suspected parts at random but I recommend a systematic approach to isolate the actual problem. That requires a volt meter, a schematic, some knowledge of simple DC circuits, and a little patience. The hardest part is finding the electrical components and sneaking the voltmeter probe into various connections.

 

[Avondale]

I had a problem with my DK 35: You can do a search on the Kioti page

http://www.tractorbynet.com/forums/...4-pto-stopped-working-my-dk35.html?highlight=

 

[Kodiak45]

Thanks guys! That's a big help. Should be an easy diagnosis and fix.

 

[TJP89]

Thanks guys! That's a big help. Should be an easy diagnosis and fix.

Not necessarily easy to diagnose, though the fix is likely straight forward. There is a lot that goes into getting that PTO to engage. I'd check safety switches and such first. Go through the manual and make sure you have fulfilled all the conditions for the PTO to engage.

Too late now, but didn't you check that the PTO worked before you bought the tractor?

 

[Kodiak45]

Either the solenoid is getting juice or not... I don't think there are any safety switches with the PTO and the only condition is if the manual/auto switch is in auto mode, which the 3pt cannot be raised past a certain point or else it wont engage until it is below that point. The manual gives no conditions for the PTO to be engaged. When I test drove it and I was looking at it with the previous owner, I turned on the PTO and I am pretty sure I heard it engage, but it had the cover over the shaft and I didn't bother to remove to inspect further.

 

[Avondale]

You are correct, manual position should engage sol regardless of 3pth position. I think there is a manual switch cct that prevents you from starting tractor if switch is on. It is very awkward to work on the wires, they are threaded through some tight spots so a few areas that could pinch/crimp a wire. To distinguish if elect or hyd issue, remove plug at sol and run 12vdc to it, if PTO spins....

 

[Kodiak45]

I finally fixed the PTO switch... at least it is working. I began by unplugging the connectors to the solenoid and testing resistance, all checked out fine. Then I went to the relays under the hood and I wasn't sure which relay was for what, so I started with the 70amp, assuming it was for the PTO (and I'm still not sure what that relay is for). After testing the relay and confirming it is working, I got on the tractor to see what was going on when the engine is running and with the relay disconnected and the PTO switch was working!!!! It is the craziest thing but for whatever reason the PTO switch is working now after doing nothing but disconnecting and reconnecting the solenoid... I hate fixes like that as my fear is when is it going to stop working again, probably in the middle of doing some work...
So the next question is what is that 70 amp relay for because I tested everything I could think of with it disconnected and it all worked... 4wd, loader, 3pt, all electrical switches, pto, etc...
Anybody have a clue?

 

[IslandTractor]

Based on what you've told us I would guess a bad connection that was fixed by disconnecting and reconnecting. I haven't had any problem with my PTO switch but I periodically manage to disconnect the wire harness below the operator station while bushhogging and I have now learned to immediately check that in the field when the 4wd stops working suddenly. The only time I have had an issue with the PTO switch is trying to start the tractor when for some reason the PTO switch was on.

 

[k0ua]

The 70 amp relay (middle one on the firewall) is for the glow plug circuit.

 

[Avondale]

MY DK35 has manual 4x4 engagement, (Pull up/push down orange T handle on left rear floor board), the switch is just for the indicator light. I have had my switch battered so often, I gave up on it.

 

[Kodiak45]

The 70 amp relay (middle one on the firewall) is for the glow plug circuit.

Do you know what the other two that are the left and right of the glow plug relay?

I need to get a service manual for this thing, the link to the German online version is helpful to an extent, just not as useful as a true service manual.

 

[k0ua]

Do you know what the other two that are the left and right of the glow plug relay?

I need to get a service manual for this thing, the link to the German online version is helpful to an extent, just not as useful as a true service manual.

Yep, the one on the left is the starter solenoid relay, and the one on the right is the Fuel shutoff solenoid pull coil relay. The fuel shutoff solenoid ( engine stop solenoid)has 2 coils the pull coil that energizes for 1 second under control of that far right relay, which in turn is controlled by the display unit controller and the hold coil which is energized by the key bus 12 volts. So the 1 second pulse comes out of the display unit, causes the engine stop relay to energize, which in turn energizes the fuel stop solenoid and then the hold coil continues to hold that solenoid energized by the 2nd "hold" coil.