Land Rover Repair: Land Rover Discovery V8 (1998) Starting Problems, land rover discovery, starter solenoid

Question
I am experiencing Starting problems with my Discovery V8. When it is driven on the motorway or on an open road and then parked, and ignition switched off, the vehicle will then not start. the power comes on but the engine doesn't turn over. it seems like something is inhibiting the starter motor. I then have to wait about half an hour and it then starts. I think it is something to do with a temp interlock inhibiting the starter circuit but the engine temp guage inside the vehicle shows normal engine temperatures. Not sure what to do, Any Ideas?

Answer
Take a test light and have an assistant see if there's power at the starter solenoid when that's happening.  If so, replace the starter.  If not, get the workshop manual and wiring book and follow the circuit back to the ignition switch.

The starter and starter relays are by far the most likely suspects.  Here in New England we see failed starters as often as anything, which is why you start there.