So. Yeah. 

My electronic boot release popped a 10A fuse, which from the Haynes circuit looks like a switch for a solenoid. 

 

I thought the fuse was just old, so replaced it and everything worked fine again. Until I used the manual boot release one day and something died again.

Now this time the fuse hasn't blown, which leads me to believe it's the switch or solenoid that's died. 

 

I measured the continuity between the two pins on the connector for the solenoid and they bell out, they shouldn't should they? 

 

What should I check next, are there common points of failure to look at first? 

Anyone know of anything in relation to this?

Possibly the motor (what you're calling the solenoid) has got wet from a screenwash leak out of the rear wiper module?

First time it shorted and blew the fuse, now the connection has just corroded from the combination of water and electricity?

 

All speculation.