156 V6 starting problem

[Damo1965]

Our Alfa 156 (2005 2.5 V6 Auto 95 000 KM) has a problem starting when it is hot. If it has been driven for about 20 minutes or more and then turned off for more than five minutes, it won't start. When the key is turned there is nothing, just a "click" from somewhere in the dash or centre console.  However, it will start if tried immediately after turning it off.
For shorter trips, it starts fine, regardless of how many times I start or stop. It is only when it gets up to temperature that the problem sets in.
When it won't start, the only sound we mostly hear is a click when we turn the key. (Sometimes it doesn't click). When it won't start, we have to wait about 40 minutes and then it will start.
Interestingly, when waiting for it to cool down, we have sometimes heard a "click" from somewhere in the dash and then it will start.
Any thoughts?

[bazzbazz]

Normally such situations are indicative of a failing crank angle sensor, except for one thing, it should still turn over, but not fire.

The fact that it does not turn over at all indicates a problem with the starter motor or the starting circuit or power supply to it.

As I am in Brisbane I have sent you a PM.

Baz