It's a 1999 e39 530d.
Recent history: It's been having issues slowly cranking for some time and the battery was replaced about a month ago. This seemed to resolve the cranking speed issue.
Today when attempting to start, the engine would not crank. Not a single noise from the starter. Battery is ok. Breakdown man called and he arrived (eventually) and connected another battery just to make sure. There is no voltage drop on the batteries when the key is turned. The car bump starts easily and runs fine. That's a little inconvenient for everyday use!
Absolutely everything else is ok. No weird electrical faults. Just the starter does not want to crank.
From what I understand, the starter is energized via a relay. I can't hear this relay click - should I be able to? The relay is energized via the EWS (immobilizer). If the EWS was faulty, would the car run fine once started? Crap EWS if that's the case.
So I think it's either a failed starter or relay, or maybe a fuse. But I think the fuse provides power for the EWS also (and indirectly the starter relay). Is there a fuse for the starter motor itself?
Any other advice on how to test the starter in this situation?