2010 DK40 SE Won't Start

k0ua · Sep 9, 2013

Step one:. You know the problem is the fuel solenoid is not pulling back correct? from you prior investigation, so lets try to find out why. The solenoid has 2 coils. the "pull coil" and the "hold coil". the Pull coil draws 32 amps of current that only lasts for about 1 second. This gets the solenoid pulled back, and the hold coil draws about .77 amps and holds the solenoid back. Here are the measurements chart and a picture. I see a discrepencie right now in which pin number is which between the chart and the picture.. But obviously the coil with the low ohms reading will be the high current pull coil terminal and the high resistance coil terminal will pull a small amount of current and be the hold coil.. So look for the 1 second pulse of 12 volts to "pull" and check for the 12 volt hold voltage.. If that does not happen, then lets dig deeper in to the relay. let me know

James K0UA

k0ua · Sep 9, 2013

here are the chart and pix.

TimbourLarry · Sep 10, 2013

Thanks kOua! I have a friend coming over this afternoon and we will work through Step One and report back.

ritcheyvs · Sep 10, 2013

TimbourLarry: While you are waiting for your friend, have you checked the fuses? There appear to be three fuses that effect the stop solenoid, any one of which would cause your symptoms. I'm looking at an EX schematic and they are labeled UNIT, Alternator/Engine Stop, and Engine Stop Solenoid on that schematic. But they may be labeled different on your machine so I'd look for any blown fuse, any fuse with corrosion on the fuse holder, or any fuse that looks like it got hot at either end. Sometimes you can't detect a bad fuse visually in which case try either a known good fuse or tesr the fuse continuity with your new meter.

k0ua · Sep 10, 2013

any news?.. after checking those 3 fuses fuses, take a look at the fuel solenoid pull coil relay.. third relay in on the firewall from the tractors right side.. could be the display unit also. notice on the schematic that the 1 second pull coil pulse comes from the display unit. to the pull coil relays coil... Do you have the Neutral lamp illuminated when you shift the range selector to neutral to start the engine start sequence? Let us know if you dont understand anything we just said.

James K0UA

TimbourLarry · Sep 11, 2013

As suggested I checked the fuses and all checked out fine. After my friend arrived we performed the check James suggested. We checked both the old and new solenoids and they both checked out perfectly. When we plugged the solenoid in and turned on the switch to crank the solenoid did not pull back, however when we manually pushed the solenoid rod in the hold pulse worked fine and it stayed in a retracted position until I turned the switch off. I just read your post from last night about the relay and yes the neutral light does illuminate during the start sequence. the only odd thing occurring on the dash board lights is the red park light never goes off and this started several weeks prior to the "no start" problem. I hope this helps and thanks again for the kind assistance.

Coyote machine · Sep 11, 2013

Are you saying the brake light indicator on the dash is on all the time when the key is in the on, crank, or accessories positions?
This should get checked out to see why it is on. You could start at the switch at the brake pedals and disconnect one wire to see if the light goes out. If yes, then switch is likely bad. I find it hard to see how this might affect the no start condition, BUT by making the light go off, if the tractor can then start you will know you're onto the culprit causing your problem and then we can further assist. Fun stuff! James and I relish doing electrical repairs in cyberspace- don't we James?:confused2::confused3:
One wire at a time, so many wires - where'd they all come from, and so many colors too....:laughing:

k0ua · Sep 11, 2013

Love it

it is a challange.. did you check to see if the Pull coil relay on the firewall operates for the 1 second.. Remember look at the schematic I posted and you can see that the coil of this relay is driven by the ground that comes out of the display unit's timer function. the other side of the relay's coil is hot with the key on voltage from the key switch. Remember this ground from the display unit is just momentary (1 second) as the key is turned to the on position. If that relay on the dash does not pull up for that one second then thee pull voltage going to the fuel solenoid will never happen.. Your doing good, keep at it.

James K0UA

kraftykeltic · Sep 11, 2013

Just A thought, but it is pertinent, all connectors are dry. Corrosion does weird things. If you have a connector with wires that you are tracing going through it open it up and check it. When checking for 12 volts with a digital voltmeter you may see voltage, but there may not be any current. Any green in a connector means you have a problem. Remember Dielectric grease is your friend.

k0ua · Sep 11, 2013

kraftykeltic said:
Just A thought, but it is pertinent, all connectors are dry. Corrosion does weird things. If you have a connector with wires that you are tracing going through it open it up and check it. When checking for 12 volts with a digital voltmeter you may see voltage, but there may not be any current. Any green in a connector means you have a problem. Remember Dielectric grease is your friend.

This is very good advice.. I would be willing to bet at least half of the electrical problems on tractors are corrosion issues.

James K0UA