DK40HST Won't Start.

k0ua · Nov 11, 2014

Coyote machine said:
Thanks for reminding me, it's been a while. Now I remember they picked a great location for a sensitive control like the cruise module; under the floorboard where it's never going to encounter adverse conditions, like water, mud, snow or dust/dirt.:confused2:

Know what you mean, but it is sealed pretty good.

Coyote machine · Nov 11, 2014

Yeah, 'till it gets hit by a branch or stump, or has to swim; like when I couldn't get out of my property line ditch/stream with my brush hog in tow, and had to wait till the next day to get towed out, hoping the water didn't rise high enough to get into critical systems and maybe even my trans or engine.... I lucked out that time.

oldpilgrim · Nov 12, 2014

does it have a pto safety switch? The Mahindra must have the pto in the off position to start.

Coyote machine · Nov 12, 2014

oldpilgrim said:
does it have a pto safety switch? The Mahindra must have the pto in the off position to start.

Yes, there is a PTO engage switch and a manual /auto PTO switch too. The PTO switch MUST be off for the tractor to start. It will never start if the PTO is engaged. Same with the range lever on the HST, it must be in either neutral position, and the potentiometer that reads neutral position must read the transmission as being in neutral. These safeties pass through the cruise control module, and if everything reads right, and only then, will the entire start circuit be closed, allowing the starter to crank, etc. Otherwise no start. Their are other items like fuses, ignition switches, etc. that can also lead to a no crank or no fuel delivery, hence a no start condition too. Each item must be ruled out by logical circuit troubleshooting. Verify, then replace, as indicated.

oldpilgrim · Nov 12, 2014

do these switches only allow the starter to crank or do they prevent the fuel solenoid and other things needed to start as well? If it's only the starter, then the OP would be able to jump it as he has been doing.

ritcheyvs · Nov 12, 2014

oldpilgrim said:
do these switches only allow the starter to crank or do they prevent the fuel solenoid and other things needed to start as well? If it's only the starter, then the OP would be able to jump it as he has been doing.

Only the starter. There are no actual switches (except the key switch). The cruise unit senses the voltage from the gear range potentiometer and the voltage from the PTO switch and connects the ground-side of the start relay to chassis ground if (and only if) the cruise unit is working and it decides the shifter is in neutral and it thinks the PTO is off.

TJP89 · Nov 13, 2014

This thread is making me glad I went with the basic CK. No complicated electrical system to fail there. The dealer disconnected every safety switch except the clutch to start one, the cruise is mechanical, as is the 4WD and PTO engagement. I'm left with the iffy fuel gauge (stays at full, then races through its range, floats at empty). As long as I don't mess something up with my lighting, I'm good to go

coobie1 · Nov 13, 2014

TJP89 said:
This thread is making me glad I went with the basic CK. No complicated electrical system to fail there. The dealer disconnected every safety switch except the clutch to start one, the cruise is mechanical, as is the 4WD and PTO engagement. I'm left with the iffy fuel gauge (stays at full, then races through its range, floats at empty). As long as I don't mess something up with my lighting, I'm good to go

Not to beat you up here but I would not broad cast to much about how your dealer disconnected safety switches.

Nick61 · Nov 16, 2014

OK, I am back home from work. I changed all my fluids yesterday cause I have 85 hours. I checked the cruise module connectors and they seemed fine. In fact, the module and all the connectors under the tractor were clean and free of dirt and mud. I checked the relays and they are fine. I also noticed while messing around that when the tractor wont turn over the battery light doesn't illuminate on the dash. Should it all way's come on when the ignition is turned on? On a side note. you all were not kidding about the filters on the tractor. Holy crap were they on their tight! I used a strap wrench that I bought at Home Depot made by HUSKY. It worked like a charm. Just kept as much pressure on it as possible and she sun off without having to remove the rear wheel or using screw drivers.

Nick

ritcheyvs · Nov 16, 2014

Nick61 said:
... I also noticed while messing around that when the tractor wont turn over the battery light doesn't illuminate on the dash. Should it all way's come on when the ignition is turned on? ...

Now this is interesting and it also points to a sick cruise unit. When the key is on and the alternator isn't turning, you should always get a battery/alternator light. Assuming your DK40SE schematic is the same as an EX schematic (and I think it is), the circuit for this indicator light is dirt simple except the ground for the light, comes from the cruise unit.

http://kioti.dyndns.org/ex_Schematic.pdf

So I think Nick has a cruise unit that fails to provide the ground for the battery light and also fails to provide the ground for the start relay when the cruise unit/module gets hot. It would be nice to take voltage readings at the cruise unit connector during the failure mode, but that's hard to do given the unit location and sealing of that connector.

I predict that the new switch and relay from the dealer will make no difference. I think we know enough to recommend replacing the cruise unit. See if you can get the dealer to send a new cruise unit.