DK35 Starter Schematics

3gGT01 · Jul 24, 2023

I have just the plain old DK35 tractor, maybe a 2008 model. I can hear the starter solenoid click when I turn the switch to the start position, but then the engine doesn't crank over. If I turn the start switch to the start position enough times, I will finally get lucky and it will crank and start. It could be the starter solenoid contactor, not sure. Had previously replaced the ignition switch, because it was worn out. I had this problem a while back and worked on diagnosing the issue when it suddenly seemed to go away. Now the same problem is back. It seems like a relay, but is difficult to troubleshoot without schematics. Does anyone have the starter circuit schematics for this model that they could post? Thanks in advance.

Harry in Ky · Jul 24, 2023

The easiest way I know of is to eliminate the start circuit entirely to begin with. Dig your way down to the starter, remove whatever plastic covers "Safety Sam" put there to prevent you from doing this. Find the start signal wire and pull it off the spade terminal on the starter. Attach a jumper wire to the spade that's long enough to reach the battery positive post on the starter. Doesn't take much. Now with key switch off, trans in neutral, three point control down, brake on, (the usual drill) briefly touch the jumper wire to battery positive. If the starter cranks, try it again and again to see if it continues to do so or if the problem "click" is there still (or again). If the starter works that way, you've eliminated the starter, solenoid, battery, and major cables as part of the problem. You need to look elsewhere. There are ways to do that too.

3gGT01 · Jul 25, 2023

Thanks for your help Harry!

I'm pretty sure it was the aftermarket ignition switch I installed a while back. In general, I tend to not buy aftermarket parts, as I'm normally not happy with the performance. This case included. The Kioti ignition switch is pretty expense, but I'll bet I wouldn't wasted all this time if I had purchased the OEM part. The plug connection wasn't that tight, so tightened the brass pin connections and appears to be ok now. So far so good!

3gGT01 · Jul 26, 2023

This morning it would not start...It continued to be intermittent, so removed all covers again and tried reseating the various connectors, but this did not help. When I put a VOM lead on the red wire of the 70A relay, it started up and appeared to be related to this relay. Before this I hooked a 12g wire from the starter solenoid to the battery and it would crank each time, so that meant it was able to start if the red wire were to get 12VDC from its' relay. Disassembled 70A relay and the contacts were a bit rough, but I've seen a lot worse. However, I resurfaced the relay contacts and so far it has been reliably starting. Tractor is back together and will continue to test for any intermittent issues going forward.

3gGT01 · Jul 26, 2023

Wanted to add this info incase it will help someone else: The difficulty in troubleshooting this issue is that a quick pulse is sent to the 70A relay, so quick that my Fluke VOM meter can’t detect 12V before it goes away. I believe a quick pulse causes the starter solenoid to interlock on until you release the key from the crank position.

I'm sure folks on this forum have a lot more info on how this system works.