DK 40 HST will not start ??

drjay9051 · Aug 12, 2014

sdef said:
With the solenoid click, I agree it sounds like a battery or cable issue as there may not be enough current available to turn over the starter. It does not take much current to run lights.

Yeah, I'll check that tomorrow.

So educate me: If it were the neutral safety switch the solinoid would not click?

sdef · Aug 12, 2014

I believe so. To me the solenoid click indicates all lockouts are working and there is not enough current to drive the starter.

k0ua · Aug 12, 2014

drjay9051 said:
Yeah, I'll check that tomorrow.

So educate me: If it were the neutral safety switch the solinoid would not click?

That solenoid is liable to be the fuel relay and the solenoid pulling back.. Your start relay (on the firewall) is a possible suspect. Three relays in a row, the start relay is first on the left, the slightly larger one in the center is the preheat relay, and the next one is the fuel solenoid relay. Swap the fuel solenoid relay with the start relay and see if the tractor will crank. It will not start because now (if the relay is defective) the fuel is shut off to the injector pump, as the fuel solenoid will likely not be energized. But this will tell you if the the start relay is the defective part. You can take it with you and get one at the auto parts store, it is a common relay. After that, without a Volt Ohm Meter, and the knowledge to use it and the schematic, you are pretty much done.

ritcheyvs · Aug 13, 2014

I assume the OP is saying the engine will not crank. "Not start" can mean many things, When the key switch is turned from "off" to "on" you should hear a LOUD click, which is the stop solenoid retracting, which then allows the injection pump to inject fuel into the cylinders. The glow relay also clicks in at the same time but it is smaller and you probably won't hear it. Only when the key is turned to the crank position should the starter relay and solenoid (on the starter) kick in.

Here's one quick test. Turn the key to ON and turn on the headlights. Then watch the headlights as you turn the key to CRANK. If the headlights go out (or almost out) there is a problem with the battery or battery cables. If the headlights stay bright there is a problem with the start logic, such as the relay James mentioned. I believe your tractor also has a neutral safety lockout (to prevent starting in gear) which could also be the problem.

There is actually a lot of "no start" experience on this list, so you will be able to fix it if you keep asking questions and providing detailed results. Good Luck!

sdef · Aug 13, 2014

Here is another thought. You can call your dealer and ask their advice. They may have seen this issue, especially on a new tractor and can offer troubleshooting advice.

My dealer is 150 miles away and I have nothing to transport my tractor to him. So I perform all of my own work. When my tractor only had a few hours on it, the grapple assembly on the bucket started working intermittently. I called the dealer for advice and he in turn called the OEM for the front remotes that the dealer installed. Between the 3 of us and a couple phone calls, the problem was fixed without any parts required. However, if needed, my dealer was willing to express ship me whatever part they thought was needed if I was willing to replace it.

I have a great dealer and hope yours is also. BTW: You need a VOM (volt- ohm meter) and need to learn the basics of how to use it.

drjay9051 · Aug 16, 2014

sdef said:
Here is another thought. You can call your dealer and ask their advice. They may have seen this issue, especially on a new tractor and can offer troubleshooting advice.

My dealer is 150 miles away and I have nothing to transport my tractor to him. So I perform all of my own work. When my tractor only had a few hours on it, the grapple assembly on the bucket started working intermittently. I called the dealer for advice and he in turn called the OEM for the front remotes that the dealer installed. Between the 3 of us and a couple phone calls, the problem was fixed without any parts required. However, if needed, my dealer was willing to express ship me whatever part they thought was needed if I was willing to replace it.

I have a great dealer and hope yours is also. BTW: You need a VOM (volt- ohm meter) and need to learn the basics of how to use it.

sdef;

As you suggested I called my dealer, Caldwell Tractor in Ocala, Fl. They were great. We were able to diagnose the issue without a multi meter, although the meter may have sped things up. I had properly working gear indicator lights on the dash when moving the shift lever and heard a faint click on the firewall (solenoid) when turning key to crank so likely not the "neutral safety switch".

Next step my dealer had me jump a wire between the + of the starter and the solenoid. Tractor turned right over.

So problem seemed to be the starter solenoid on the firewall. He next had me switch the wires between the starter solenoid and fuel solenoid. Again started right up.

So the issue is clearly the start solinoid and one is on order.

Of course if I need the tractor this weekend i could always jump at the starter.

Oh yes for those who are wondering the start solinoid and fuel solinoid are identical so so worries about doing electrical damage.

I am curious whatexactly does the fuel solinoid do? Run the fuel pump? I imagine if I did not swith wires back to original position tractor would have run put of fuel?

Thanks everybody for your help. i appreciate it.

I'm glad I called dealer as suggested and did not start taking apart the key switch.

Thanks again

k0ua · Aug 16, 2014

The fuel solenoid relay energizes one of the coils of the fuel stop solenoid which lives on the front of the injector pump. The injector pump pumps high pressure fuel to the fuel injectors that spray fuel into the combustion chambers. The fuel stop solenoid has two coils. It has a "pull" coil which requires high current, about 28 amps and the relay on your firewall switches that on for about a second.

This causes the solenoid to pull back the fuel rack in the injector pump. The second coil on the fuel stop solenoid is the "hold" coil. Which requires a fractional portion of an amp of current to hold the fuel rack back. So you have a very large current to get the solenoid moving and a very small current to hold it back. This small current is supplied from the "on" key buss and does not go thru that relay.

When you turn the key off this small hold current no longer flows and a spring snaps the solenoid the other direction to close the fuel rack, the fuel is no longer delivered to your injectors and the tractor engine stops running.

The solenoid works on the theory that it can take a very large current to overcome the spring and get the mass of the solenoid armature moveing but only a small current to "hold" that same solenoid in that position. So there you have it, a long drawn out answer to your simple question

I am glad you got your machine going with a minimum of trouble. If you ever do need to tear into to your key switch, be sure to see my thread on tearing down the steering column shroud.

http://www.tractorbynet.com/forums/...i-dk-throttle-lubrication-pix.html?highlight=

Illini22 · Aug 16, 2014

I think I'm going to pick up a few of those solenoids, it's probably just a matter of time before one fails. They are small enough to carry in my toolbox so I would always have them. Someone mentioned that it's a generic part that can be bought at an auto parts store. Does anyone have the parts number handy? My service manual is with the tractor at another location. I tried michigan iron, but couldn't figure out how to register to search there website (only allowed you to sign In, but not register). I can keep searching some old threads here too.

k0ua · Aug 16, 2014

I don't have any part numbers for you, but this diagram of the start relay and the fuel shut off relay (they are the same type of relay) may help. The coil is between the 85 and 86 terminals and the contacts are the 87 and 30 terminals. Probably best to take in one of the relays with you to the auto parts store. and find one of the same rating and terminal layout.