Good test. This is getting interesting in a nerdy way.
Attached ammeter lead and again ok engages and disengages.
Attached smaller brown wire and good same again.
Attached red and white ign lead and using rubber push good.
But, turn ignition key and zilch, nowt, will not turn the engine.
So, at this point the solenoid is free hanging, not attached to bulkhead so me thinks earthing.
Attach jumper lead to Earth and solenoid and hey presto ignition key turns the engine.
But, wiring diagrams do not show the solenoid needs to be earthed, so me thinks I got an earthing problem ?
Or does the solenoid need to be a good earth through the attaching screws ?
Edit as a note it did not stick in any of the above tests.
Edited by RobG, 29 June 2018 - 07:39 PM.