John Deere D110 Not Starting

[oldcoot]

When I try to start mower I get a lot of rapid clicking noises coming from the solenoid. I've read several guidelines on how to test solenoid by jumping the two solenoid posts to see if engine will start. I'm confused about what the ignition should be set on when doing this.... OFF or ACCESSORY.......or do I jump the posts while at the same time turning key to START. Do I have to be seated when doing this in order to bypass safety switch?? And if I'm understanding correctly, if the engine starts when I jump the solenoid that means the solenoid is bad, but if engine fails to start then the starter is bad ?? Any help is GREATLY appreciated.

 

[Woodtroll]

Rapid clicks or chatter from the starting solenoid usually means a bad or partially discharged battery, or corroded battery terminals, in my experience, caused by the sloenoid not having enough energy to "latch" the contacts completely under load.

If you're jumping the two heavy posts, the starter (if good) will usually crank regardless of key position, but the engine will only start and run if the key is turned on. Some mowers may be wired differently, but this usually works. Don't use a good screwdriver or tool, as the arc from jumping the terminals under load (the starter) will usually burn a hunk out of the metal. Be prepared for the spark, too! But do check your battery voltage and battery terminal connections first.

 

[Shane¹]

I would agree with @Woodtroll usually clicking is low battery. Usually if starter was bad solenoid wouldn't click rapidly starter would simply not spin and if it was the solenoid it would just click once but starter not crank also. Jumping it then would rule out if solenoid is bad internal. But you could simply check with a volt meter much easier. Battery voltage static, voltage incoming to solenoid, voltage out of solenoid when trying to crank, and voltage at starter

 

[stretch5881]

I'm also going to say battery. When the battery is rested for at least 1 hour (no charger on it), it should have at least 12.3 volts. If it's below 12, it's shot.

 

[066 redeye]

you can also put jumper leads direct from battery to starter motor.
This will prove battery and starter bypassing solenoid.