My John Deere riding lawn mower LA100 will not start? I have replaced the starter, solenoid, relay switch, ignition switch, placed a new battery on and all it does is click in the solenoid.

Hi,
There is a bad connection somewhere. Since you have replaced those items and all you hear is a click, something else is wrong. I might suggest placing your hands on the flywheel screen on top of the engine and turning about a half turn counter-clockwise to make sure it is not the starter pinion wedged on the ring gear. If that is not the case. It is time to explore the connections.
Peace,
Clarke

How do you take the ignition switch off