JD870 Will Not Start

   / JD870 Will Not Start #1  

NWL

Member
Joined
Aug 6, 2008
Messages
30
I last used my JD 870 about 6 weeks ago and all was fine. I got on it the other day, turned the key, and nothing. The dashboard lights come on, headlights work, but it will not even try to turn over. I get nothing when trying to start. Charged the battery, gear shift in neutral, PTO disengaged, and there is power to the starter. Today I plan on taking the battery out and giving it a good cleaning and check the fluid level. I have read the other posts concerning starting problems and learned about the solenoid, but I have no idea what it looks like or where it is as my owner's manual does not show it's location.

Any information you folks can provide will be greatly appreciated!!!
 
   / JD870 Will Not Start
  • Thread Starter
#2  
Update: Cleaning the battery and connectors did not solve the problem. :( Please folks, I need your input! 20 some people have looked at my post, but none have left replies.:confused: I'm open to any and all suggestions! Thanks:)
 
   / JD870 Will Not Start #3  
If your starter looks like the one in the picture, the large wire should be hot at all times and the small wire should only have power when the key is in the start position. If you have power at these locations then the problem is probably the starter (assuming there are good connections at the starter). If you don't have power at either of these connections you will have to trace back the circuits to find the problem. You can jumper power from the large wire to the small wire terminal of the starter to see if the problem is coming from the ignition switch (Warning: This will engage the starter). Also, you can work the starter mounting bolts in and out to make sure you have a good ground.

pict0151xt2.jpg
 
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   / JD870 Will Not Start #4  
NWL,

and there is power to the starter
How did you ascertain this? You measured voltage where? (And note that the presence of 12V doesn't imply that there is any power available; it just means it might be available.)

truckie36's post does apply to your 870, and the picture is close. The "always hot" wire will be a heavy gauge black wire, and the "hot when cranking" will be a lighter gauge wire which is white.

As truckie36 says, check for voltage on both wires when the key is in the spring-loaded crank position. And as truckie36 says, "If you have power at these locations then the problem is probably the starter (assuming there are good connections at the starter). ".

If you don't have about 12V on the white wire, then there could be a problem with a "neutral start" relay which must be closed in order to for voltage to be present at the white wire.

The "neutral start" relay is closed/energized only under "safe conditions" which involve several components. The key must be on (could the key switch be bad?) The seat safety switch must be closed, either because there's weight on the seat, or it's been defeated by tilting the seat forward and pulling up on the switch.

In addition, the seat switch must be closed for some length of time (pretty short, maybe 1 or 2 seconds, so if you hit a bump and bounce up off the seat, the tractor doesn't shut down). There's a "time delay control module" that provides for this delay.

The PTO safety switch and transmission-in-neutral switches are also involved. For a hydrostatic transmission (was it available for this machine?), the park-brake switch would also be involved.

Here's a series of tests:
0) Double check that you have PTO off, transmission in neutral, and for good measure, the parking brake set (that's normally only for hydrostatic transmission machines).

1) Then, with weight on the seat, and key in spring-loaded "crank" position: There should be 12V on the white wire at the starter. If so, some part of the starter or starter solenoid is bad (they're one unit).

2) If no voltage under those conditions, .............let me know and I'll post further instructions.
 
   / JD870 Will Not Start
  • Thread Starter
#5  
Thank you truckie36 and TedLaRue for your suggestions! :D My father only checked "the always hot wire", so now we know that there is another one to check. :eek: We'll try again today and I'll post the results later.

Thank you both for taking the time to help me!!!:)
 
   / JD870 Will Not Start
  • Thread Starter
#6  
Thunderstorms moved in and kept us from trying your solutions (sadly, I do not have cover for my 870 at this time. It's on my "to do" list.:D ) I will post as soon as we get a chance. It may not be for a day or two. Thanks again for your help!
 
   / JD870 Will Not Start #7  
Disengage the PTO and sit on the seat.
 
   / JD870 Will Not Start
  • Thread Starter
#8  
zzvyb6 said:
Disengage the PTO and sit on the seat.

zzvyb6: Pto is disengaged, it's not in gear, and I was sitting on the seat. Any other ideas?
 
   / JD870 Will Not Start #9  
(This is not a standard OEM recommendation..) But, you can use a screwdriver to short across the terminals (the big red wire and the little white wire) on the selenoid to "jump" the starter. You'll get a big spark and it will likely burn a spot on the screwdriver; but the starter should engage and the engine should start (if the key is on).

If the selenoid is bad, the starter won't engage and you'll hear a good click and whirr; but no go on the engine. If the starter is bad you should hear a good click and a clunk; but no go on the starter and engine.

Sometimes the starter bendix will engage onto the flywheel and just hang there -- and the next time you want to start the engine it's a "no go". When that happens; the next time you turn the key, all your instrumment lights will dim and the selenoid clunks and nothing else happens -- starter doesn't spin, etc.

Best of luck and please let us know how things turn out.

AKfish
 
   / JD870 Will Not Start
  • Thread Starter
#10  
Update: Tried TedLaRue's suggestion of checking the hot when cranking wire, and thanks to truckie 36's picture, I could find it.:) Assuming we did it right, we did not get any indication of voltage at that wire. Any ideas as to what we should check next?

Thanks again to everyone who has posted their thoughts on this problem :D
 
 
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