So yes, secondary air pump. Looks like either a removal and try to fix or a new one (eBay).

 

350504799784

So for £50, might as well just get another...

 

From reading a few other threads on this, it could be the relay rather than the pump itself.

Thanks for the hint Gary

I really need to get behind the bumper and take a look

 

Well, it's definitely the air pump.

The electrical connector decided to part company with the body of the air pump itself, so no wonder the damned thing wouldn't run!

Looking at the pins, I'd say water ingress was the cause of the problem.

Coincidentally, I also had to change a headlight connector today for the same reason.

 

Speak to Dixon - he may have a few. He removed mine.