JD 2940 Starter Solenoid Question

[FlyingG]

I have a situation on my tractor and I need some help with it. I have a push button start on my tractor and occasionally when the humidity was high you could hit the button and get nothing. I could short across the lugs on the solenoid and then it would work fine. I took that as the solenoid switch going bad. I finally went to napa and bought a new solenoid and this is where things went strange. I hooked the new solenoid to the starter and Hooked it all back up and on the final step I hooked up the cable from the batteries and the starter spun on contact! I then went on to remove all of the wires from the solenoid except the cable that connects to the starter and when I touched the battery cable to the solenoid still it would spin the starter but neither time would it engage on the flywheel. At this point I'm convinced its a bad solenoid. I go to JD get a Bosch solenoid from them take to the shop and hook it up only to find it does the exact same thing! I am at a loss as to how when you hook a battery to a solenoid that all of the lugs could be hot. I took just the solenoid in my hand, grounded the case to the frame and hooked the battery cable to the appropriate lug and with a test light you get voltage on all of the lugs, on both of the newly purchased solenoids. Am I losing my mind here or is there something I'm missing? Any help on should have been a simple repair is greatly appreciated.
Matt

 

[Tx Jim]

Even though this starter relay kit isn't listed for your 2940 by chance has it been field added? Is the wire that attaches to the starter solenoid "S" post without electricity when it's not attached to solenoid with ign switch in off position?

 

[FlyingG]

Yeah this machine has nothing extra added to it. The only thing the ignition switch does that I am aware of is allow the alternator to charge the battery and energize the instrument panel. One wire comes off of the start button to the battery fed side of the solenoid and the other wire off of the starter button goes to the only small lug on the solenoid. The bottom lug on the solenoid connects to the starter. To me the small lug should only have voltage when I push the start button and through the solenoid it should then put voltage on the bottom lug engaging the starter.

 

[mikefamig]

Is this like an automotive solenoid that has a spring in it that disengages the switch when it's not energized and did you install it correctly?

 

[Tx Jim]

Yeah this machine has nothing extra added to it. The only thing the ignition switch does that I am aware of is allow the alternator to charge the battery and energize the instrument panel. One wire comes off of the start button to the battery fed side of the solenoid and the other wire off of the starter button goes to the only small lug on the solenoid. The bottom lug on the solenoid connects to the starter. To me the small lug should only have voltage when I push the start button and through the solenoid it should then put voltage on the bottom lug engaging the starter.

According to JDparts.com the only push button on a 2940 I see is the horn control switch not that will solve your tractors electrical problem. I wonder when you installed solenoid if somehow you managed to pull fork to engage starter gear which in essence would make washer inside solenoid contact both lugs.?? Did the starter just spin or did the engine also spin when battery cables were attached??