DK50SE HST Wouldn't Start

[SwingOak]

I went out to clear off the 10" or so of snow this morning, I turn the key, and nothing. Wiggle the range selection lever making sure it's in neutral, and nothing. Not even a click.

So I launch an investigation. Thinking it might be a bad switch or whatever, I looked up this post: http://www.tractorbynet.com/forums/.../302554-dk40se-hst-neutral-safety-switch.html, in which I found some interesting news about the shift position sensor. The photo showing the resistance values and voltage readings was very helpful.

Armed with this information, and sure it was the shift position sensor not reporting that it was in neutral (even though all the dash lights worked OK), I removed the seat pan to check it out.

NOTE: If you have a cab model like mine, remove the seat from the seat pan first. That assembly is HEAVY and very awkward to maneuver with the seat pan attached. I scratched up a few things muscling it out & hauling it back into the cab later.

I had a tough time getting the plug to the switch separated, but when I did the switch tested OK - about 1.8k Ohms, with each position reading a percentage of full scale as would be expected - 0, 0.45, 0.9, 1.35, and 1.8k Ohms. The power supply was about 4.5 VDC.

I removed the ignition switch and took it with the housing attached into the shop to test it, because it was -2°F out so why work outside if I don't have to?

The switch tested fine. Hmm...

I reinstalled the key switch and housing, hooked up my meter to the ignition wire at the starter, and it read 10.7 VDC to ground when I turned the key switch.

Hmm...

So I put everything back together, seat back in (scratching a few things in the process), turned the key to the run position, and when the glow plug light went out I used a short piece of wire to jump between the battery terminal and the ignition wire terminal on the starter solenoid. It cranked over and fired right up.

Not wanting to waste any more time because I couldn't feel my face anymore, I put all the covers back on, closed the hood, and went to work clearing all the snow I needed to move.

When I was done, I parked the tractor in front of the shop and shut it off. Turn the key again and it started right up.

This is not the first time it has done this, it started acting up a bit in the fall, but only rarely - which is what made me think it was the shift position sensor. Now I'm thinking it's the ignition switch not delivering enough voltage to the starter solenoid. Maybe. At least now I know what I need to do to start it when it doesn't want to work properly.

Any thoughts?

 

[k0ua]

I went out to clear off the 10" or so of snow this morning, I turn the key, and nothing. Wiggle the range selection lever making sure it's in neutral, and nothing. Not even a click.

So I launch an investigation. Thinking it might be a bad switch or whatever, I looked up this post: http://www.tractorbynet.com/forums/.../302554-dk40se-hst-neutral-safety-switch.html, in which I found some interesting news about the shift position sensor. The photo showing the resistance values and voltage readings was very helpful.

Armed with this information, and sure it was the shift position sensor not reporting that it was in neutral (even though all the dash lights worked OK), I removed the seat pan to check it out.

NOTE: If you have a cab model like mine, remove the seat from the seat pan first. That assembly is HEAVY and very awkward to maneuver with the seat pan attached. I scratched up a few things muscling it out & hauling it back into the cab later.

I had a tough time getting the plug to the switch separated, but when I did the switch tested OK - about 1.8k Ohms, with each position reading a percentage of full scale as would be expected - 0, 0.45, 0.9, 1.35, and 1.8k Ohms. The power supply was about 4.5 VDC.

I removed the ignition switch and took it with the housing attached into the shop to test it, because it was -2ｰF out so why work outside if I don't have to?

The switch tested fine. Hmm...

I reinstalled the key switch and housing, hooked up my meter to the ignition wire at the starter, and it read 10.7 VDC to ground when I turned the key switch.

Hmm...

So I put everything back together, seat back in (scratching a few things in the process), turned the key to the run position, and when the glow plug light went out I used a short piece of wire to jump between the battery terminal and the ignition wire terminal on the starter solenoid. It cranked over and fired right up.

Not wanting to waste any more time because I couldn't feel my face anymore, I put all the covers back on, closed the hood, and went to work clearing all the snow I needed to move.

When I was done, I parked the tractor in front of the shop and shut it off. Turn the key again and it started right up.

This is not the first time it has done this, it started acting up a bit in the fall, but only rarely - which is what made me think it was the shift position sensor. Now I'm thinking it's the ignition switch not delivering enough voltage to the starter solenoid. Maybe. At least now I know what I need to do to start it when it doesn't want to work properly.

Any thoughts?

When you say "nothing", I assume you mean it won't crank. In other words, the starter does not pull in and rotate. The key switch does NOT directly control the starter solenoid. It cannot carry enough current to do this. There is a starter relay on your outside firewall . It is the first relay on the left as you look from the engine towards the cab. This is a likely culprit, BUT it is under control by several other things. The PTO must be off, and a ground must be thrown by the cruise module to the low side of coil of the start relay. Remember the contacts of the start relay energize the starter solenoid, but the coil of the start relay is energized by the key switch for the +12 volts and the low side is grounded by the module that determines that the PTO is off and that the range selector is in Neutral. Only then will the start relay pull up, and it in turn pulls up the starter solenoid.

The start relays are a common failure, and you can use generic ones from the autoparts store. But keep in mind there are many things that can keep that relay coil from pulling up. Cruise module, PTO control relay, PTO switch, the diode in the ground side of the start relay coil, etc. etc. But do the easy and most likely thing first, and change out the start relay.

 

[murphy1244]

James :thumbsup: Da-m your good.

 

[MinnesotaEric]

I went out to clear off the 10" or so of snow this morning, I turn the key, and nothing. Wiggle the range selection lever making sure it's in neutral, and nothing. Not even a click.

So I launch an investigation. Thinking it might be a bad switch or whatever, I looked up this post: http://www.tractorbynet.com/forums/.../302554-dk40se-hst-neutral-safety-switch.html, in which I found some interesting news about the shift position sensor. The photo showing the resistance values and voltage readings was very helpful.

Armed with this information, and sure it was the shift position sensor not reporting that it was in neutral (even though all the dash lights worked OK), I removed the seat pan to check it out.

NOTE: If you have a cab model like mine, remove the seat from the seat pan first. That assembly is HEAVY and very awkward to maneuver with the seat pan attached. I scratched up a few things muscling it out & hauling it back into the cab later.

I had a tough time getting the plug to the switch separated, but when I did the switch tested OK - about 1.8k Ohms, with each position reading a percentage of full scale as would be expected - 0, 0.45, 0.9, 1.35, and 1.8k Ohms. The power supply was about 4.5 VDC.

I removed the ignition switch and took it with the housing attached into the shop to test it, because it was -2ｰF out so why work outside if I don't have to?

The switch tested fine. Hmm...

I reinstalled the key switch and housing, hooked up my meter to the ignition wire at the starter, and it read 10.7 VDC to ground when I turned the key switch.

Hmm...

So I put everything back together, seat back in (scratching a few things in the process), turned the key to the run position, and when the glow plug light went out I used a short piece of wire to jump between the battery terminal and the ignition wire terminal on the starter solenoid. It cranked over and fired right up.

Not wanting to waste any more time because I couldn't feel my face anymore, I put all the covers back on, closed the hood, and went to work clearing all the snow I needed to move.

When I was done, I parked the tractor in front of the shop and shut it off. Turn the key again and it started right up.

This is not the first time it has done this, it started acting up a bit in the fall, but only rarely - which is what made me think it was the shift position sensor. Now I'm thinking it's the ignition switch not delivering enough voltage to the starter solenoid. Maybe. At least now I know what I need to do to start it when it doesn't want to work properly.

Any thoughts?

If it isn't a start relay shelling, I found out in 2014 that if I leave my Kioti tractor parked with the parking brake on for a week or so in the summer, the brake safety switch screws up in high humidity. The switch needed to be exercised (i.e. on/off-on/off-on/off and so forth) in order to clean up the contacts and start working again. If you're parking your tractor in a heated garage making everything sweat, I bet you have a similar problem.

 

[k0ua]

James :thumbsup: Da-m your good.

I try to help when I can Murph. My only wish was I got to him before he unbolted his seat and took out the range selector pot. I will give him this, he is ambitious, It is too darn cold out for me to work on a tractor, or I am just too darn old...

 

[murphy1244]

I try to help when I can Murph. My only wish was I got to him before he unbolted his seat and took out the range selector pot. I will give him this, he is ambitious, It is too darn cold out for me to work on a tractor, or I am just too darn old...

You know the older we get the colder it seems. I will take you on my team anyday.:thumbsup:

 

[k0ua]

You know the older we get the colder it seems. I will take you on my team anyday.:thumbsup:

Thanks Murph

 

[kco]

When you say "nothing", I assume you mean it won't crank. In other words, the starter does not pull in and rotate. The key switch does NOT directly control the starter solenoid. It cannot carry enough current to do this. There is a starter relay on your outside firewall . It is the first relay on the left as you look from the engine towards the cab. This is a likely culprit, BUT it is under control by several other things. The PTO must be off, and a ground must be thrown by the cruise module to the low side of coil of the start relay. Remember the contacts of the start relay energize the starter solenoid, but the coil of the start relay is energized by the key switch for the +12 volts and the low side is grounded by the module that determines that the PTO is off and that the range selector is in Neutral. Only then will the start relay pull up, and it in turn pulls up the starter solenoid.

The start relays are a common failure, and you can use generic ones from the autoparts store. But keep in mind there are many things that can keep that relay coil from pulling up. Cruise module, PTO control relay, PTO switch, the diode in the ground side of the start relay coil, etc. etc. But do the easy and most likely thing first, and change out the start relay.

View attachment 492024
View attachment 492025

Very nice clear explanation, James.

Another way to check if the start relay is the problem is to switch it with the stop(fuel) relay. They are the identical small relays. The larger relay is the preheat relay. If all else is OK the tractor should crank, but it will not start because the faulty relay is now the fuel relay. At least if it turns over it will confirm the other components in the start circuit are working.

 

[SwingOak]

I apologize for not posting a follow up to this, it's been a long time, and this is going to be a long post but I've got a lot to talk about here.

This particular problem has occurred several times over the past few years. When I made this original post I drove around with a hotwired tractor, completely bypassing the ignition switch for the rest of the winter. I finally ordered a new switch, and before I put it in, I tried the old switch again. Nothing - it didn't start, so although the switch continuity checked fine appeared to be the culprit.

New switch in, and bingo, problem solved. No issues for about three more years, then the same thing happened. Ignition key switch checked out OK, and I was able to start it by bypassing the key switch entirely again. Not again, I said. But then, the key switch started working again, and it was fine again up until spring of this year, 2021. Did it again.

I hotwired the tractor again and this time, nothing. I tapped on the relays, and nothing. Checked the range selector switch again, and it's fine. Hmm. Gave up on trying to fix it because I had to travel out of state for work, so I called my dealer who sent someone a couple of days later. I arrived home from the airport to find him in my driveway, tractor running.

He said he held the key in the run position, and wiggled the range selector around for about 20 minutes and it started. He said it might be a relay too, (exactly like k0ua said), but wasn't sure which one of the three on the firewall it was. This time, it was the relay, because when it failed to start again the next day, I tapped on the relays again and it fired right up.

I picked up replacements for all three relays (well, one each of both types), but still have not installed them because it started working again. I only had to tap on the relays one one other time I think in June of this year, and as I had hauled it 200 miles from the farm to work on my land in the UP and I did not have the spare relay with me.

And it worked fine after that, and promptly forgot about replacing the relay.

Now, I had a problem (again while traveling of course) where the tractor died when my GF was putting hay out for some of the horses, and it was dead. Nothing, no lights, no power, not even flashers. That turned out to be the power wire on the back on the alternator rubbed on the metal wire holder bracket and shorted to it. I pulled the wire free and it started right up. Wrapped the wire in electrical tape, and problem solved.

So just this weekend on Friday, one of my boarders was here cleaning up, and was using the tractor. No issues. Saturday morning, my girlfriend goes to drive down to the end of the driveway to pick up the garbage cans and it won't start. Not even the lights came on.

I checked everything - battery is good, starter cranks the engine over when I direct connect the solenoid to positive battery terminal. I pull the steering column apart and check the ignition switch plug. It's dead, no power there at all. Nothing worked except for one thing - the interior light. At that point, there's only one thing it could be.

I pulled both main power fusible links in the harness next to the starter, and checked continuity. Both were in good shape. But then I looked closely at the socket, and one of them was dirty and had what looked like mud in it. Well, of course, I had the tractor stuck and buried up to the axles almost 3/4 of a mile back off in the woods away from the main road on my land up north. Mud got everywhere, and apparently it got into the the fusible link socket (which was only "sealed" with crusty and worn out electrical tape) and eventually caused the connection to lose connectivity. I cleaned the contacts on the fusible links and sockets and problem solved.

I still haven't replaced the starter relay, but the spare is on the shelf.

OK, that's the update, and I'll post a short summary of my learning experiences on this issue in another post because I had a lot to cover here, and I know someone in a hurry with this same issue is going to want the short version...

 

[SwingOak]

Summary:

If your Kioti won't start:

Ok, this all assumes that battery is OK and charged -

1. If battery is fine and you have no power anywhere except to dome light (on a cab tractor), check the fusible links in the wiring harness next to the starter on the left side (left being relative to driver operating position).
2. If tractor dies for no reason while running, and is completely dead (not even flashers) check for a short in the charging wire on the alternator.
3. Power to dash lights and in Acc/run position, but tractor doesn't start, tap on the relay on the left of the three relays on the firewall, as viewed from the front of the tractor looking towards the rear.
a. Try swapping relays 1 and 3, they are the same part.
b. If you have a helper turn the key to the start position, if you put a finger or two on relay 1 you should feel it click on.
4. If tractor won't start but there is power on the dash lights and relay checks out ok, disconnect the ignition switch.
a. Make a 3 way jumper wire by crimping two spade terminals on one end of two short pieces of wire and using a 3rd spade terminal to connect the other ends., I used 18 gauge which didn't even get warm.

b. Connect jumper as shown. Note that the drawing is the view looking at the tractor side plug, not the switch.

c. Connect the single spade terminal with the two wires attached to the terminal with the large red wire (12v hot wire) Terminal 1.
d. Connect one of the other spade terminal to terminal 4 in the picture. This is the same as the "Run" position of the switch as far as the ignition is concerned.
e. When the glow plug light goes out, touch the other spade terminal (do not plug in) to terminal 5. This will energize the starter and start the tractor, as this is the same function as the "start" position of the switch.
f. When the tractor is running, plug this last spade terminal on the jumper wire into terminal 3. This will allow all the accessories to work normally. This is the same function as the "Run" position of the switch.
g. Connecting terminal 1 to 3 and no other terminals is the same function as the "Acc" position of the switch
5. If the tractor has power, all lights work, and hotwiring to bypass the ignition switch does not work, then the most likely problem is the shifter range selection pot. I incorrectly called this a switch in my earlier post, this is a potentiometer that provides a resistance range to the computer, which both tells the tractor programmatically which gear range light to turn on, and whether it's in neutral for permissible start.
a. If the shift range lights on the instrument cluster flicker or turn on/off, go out, or change indicated range while moving the shift lever between ranges, you might have a bad range selector potentiometer.

That's all I got so far, I hope somebody will find it useful and learn from my mistakes!