Non start, sticking starter, stranded, sudden start!

At the boys school this morning, chilling while waiting, and listening to Motorhead and Monster Magnet. Turn the key, and nothing, nada zilch.

Not even a click from the starter

Hammer out, smack the starter, no joy.

Call a friend, on his way, then a roll back down the hill in reverse, and it fires up! Turn off, restarts on the key.

Cancel friend, drive home, now all good and starting well!

I have checked the exciter wire - it seemed a little slack on the connector, but the starter looks new, but cheap..... no identifying marks...

Time will tell if it needs replacing, but I have been having symptoms where I turn the key, and there is a half second pause before anything happens....

Looks like you have found the problem. The connector to starter solenoid is a common problem.

I had similar on my 300tdi, turned out to be a loose connector to the solenoid (is this what you call the exciter).

Thanks for the reassurance - after a quick squash of the connector with pliers, it does seem a little more eager to start - time will tell!

Mine would start fine with normal running, but if I had been towing on long journeys (engine working hard for some time) the starter would be dead, nothing at all when turning the key until it cooled down a bit.
Once I replaced the connector it's been fine for almost a year.