Kioti 40HP will not start

[Pet982]

Hello New-B here! I hope you all can help me out on this one.



I work at a children's summer camp and we have a 2010/11 DK40 HSE that keeps blowing the 25amp and 10amp fuse for the stop solenoid. It started as the 25amp like every 5th start, so then we replaced the solenoid. It now has moved to the both every time the key is switched on WITH the solenoid plugged in. We switched the starter and solenoid pull relay and the problem followed. I used a MM and see that (after the glow plugs turn off) I get 12V on both the pull and hold circuits (10V with them lit), however the the pull circuit never goes to 0v no matter how long I wait.


I only work there part time (Mondays) during the off season and was told by the full time guy that he took the ignition switch off and cleaned it and now the 10amp no longer pops. I don't know what he did or how he did it. The rest of the diag. that has been done and mentioned here I have done personally.


Thanks!

 

[ritcheyvs]

It's odd for both fuses to blow. I would check the wiring carefully for a possible short where insulation is worn away. The 10 amp fuse feeds only the stop solenoid hold coil (which it can power continuously) and the alternator regulator so it's hard to understand why this fuse would blow unless there is a wiring short or a bad stop solenoid.

Are you saying no fuses blow if the stop solenoid is not plugged in?

What did you mean when you say the problem followed when you switched relays?

The PULL signal should be a one second 12v (approx) pulse that should go to zero volts after one second. If it is stuck at 12v that would probably blow the fuse. That pulse is switched by the stop solenoid relay and controlled by the display unit, which provides the ground to the relay coil for one second.

Maybe the relay contacts are welded together? Maybe the ground wire from the relay coil to the display unit is shorted to ground? Maybe the display unit is bad? Maybe you got a bad replacement stop solenoid?
These are fairly simple circuits to troubleshoot if you can find

 

[Pet982]

Are you saying no fuses blow if the stop solenoid is not plugged in?

What did you mean when you say the problem followed when you switched relays?

Correct no fuses blow when the solenoid is not plugged in.


Yes when I switched the relays the fuses kept blowing.

I didn't take apart the ignition switch but could that be shorting out?


and the fact that I get 12v constant is an eyeopener for me. Should I be looking at the display unit?

 

[ritcheyvs]

...
Yes when I switched the relays the fuses kept blowing.
I didn't take apart the ignition switch but could that be shorting out?
and the fact that I get 12v constant is an eyeopener for me. Should I be looking at the display unit?

To be sure you identified the SS relay: with the SS disconnected and a meter on the pull wire indicating 12v, pull the connector off the SS relay and confirm the pull voltage drops to zero. That will guarantee you truly know which is the SS relay.

Now, again with the SS disconnected, the SS relay connected, and a meter on the pull wire reading 12v, pull the connector from the display unit. If a bad display unit was causing the continuous pull voltage, that should cause the voltage at the pull wire to drop to zero.

When I say "the pull wire" I mean the "pull" side of the SS connector.

If pulling the display unit connector does not cause the voltage to go to zero there may be a short in the wires or the relay is failed in the closed position (probably the cheapest and easiest thing to fix).

Did I understand correctly that you bought and installed a new SS and the problem didn't change except the 10 amp fuse also started blowing?

Cleaning the key switch should have no effect on those fuses blowing (cleaning could effect other things).

I would still inspect the wires closely, especially where they pass through metal. Shorts can be created or corrected accidently by moving wires to do other things, like disconnecting connectors.

 

[Pet982]

Today I rechecked the wires and tested with the solenoid unplugged. After the key switch was taken apart, now the 10 amp fuse does not blow anymore and I am now getting 12V for that one second. For the heck of it I took the solenoid out and with the 25amp fuse out I turned on the key and pushed the pin in and it held. However it still pops the 25amp when plugged in.

I got the thing started and drove it the mile out of the woods back to the shop with the SS out and used a screwdriver to shut it down.

The new SS ohmed out at 2 on the pull side and the original at 15 not 28 like the book says. I also hooked both up to a battery to energize the pull side and the wires sparked and got hot but no pull. I went to the dealer to see what they would do with the bad SS and he went over his book and called Kioti. He has it down to the 2 things left that could have caused the SS to go bad.

Bad key switch energizing the pull solenoid for too long causing it to burn out. or bad display unit (controller)

 

[MinnesotaEric]

Replace the stop solenoid relay.

 

[ritcheyvs]

It sounds like you have a truly bad stop solenoid. But why? The fact it did not retract with +12v applied directly from to the pull terminal to the case is conclusive (you did apply 12v to the pull terminal and ground the case, right?). Two bad stop solenoids would be very odd unless you have another problem that is killing these solenoids. I only recall one or two other reports of a really bad SS here on TBN (although several good ones were replaced).

Are you sure about the continuous 12v seen previously at the pull wire? If that was really the case and it happens again it might kill the next SS too. It is possible that the pull coil was energized for an extended time (either from a sticking relay or bad display unit) causing it to overheat and create shorts within the coil winding (possibly both the hold and pull coils). The SS isn't prohibitively expensive but you need to find the root cause. You might (for example) rig a 12v bulb (where you can see it) from the pull wire so you can visually confirm the pull pulse is turns off.

I think the key switch had nothing to do with the problem. Don't put too much faith in the resistance readings for the pull coil. The pull coil is supposed to draw about 20 amps (for one second). That implies a resistance less than one ohm. Your average consumer multimeter is pretty useless down that low. But if you applied 12v with the correct polarity and it did not retract the SS is certainly bad.

FYI, there should be a manual stop lever in the vicinity of the injection pump to stop the engine by hand without the screwdriver.

 

[Pet982]

I'm not sure what the tech did when he took the new SS in the back to test it but he said it didn't work when he put power to it too. I connected the battery leads to the posts themselves I didn't ground to the SS case.


The relay is brad new but again I don't know if the key switch was cleaned before or after the relay was changed. (maybe the 10 fuse problem being corrected is relay from new relay and not the switch) The tech is thinking that with vibrations the switch could have been sending signals to the display unit.

 

[ritcheyvs]

...The relay is brad new but again I don't know if the key switch was cleaned before or after the relay was changed. (maybe the 10 fuse problem being corrected is relay from new relay and not the switch) The tech is thinking that with vibrations the switch could have been sending signals to the display unit.

I suppose it's possible the key switch made intermittent contact, constantly resetting the 1-sec pulse so it was almost continuous but I tend to doubt it. That signal from the switch comes from the same contacts that power almost everything on the tractor so if this were happening it seems other circuits/loads would act odd too. Besides, the OP reported a continuous 12v (instead of a pulse) with the engine stopped (no vibration). Bottom line is I think the owner will need to monitor this thing once it's working again.