Dk40se pto switch

[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.