Right... I'm beginning to think that a lot of this could be battery-related.
After the newly-charged battery was reconnected (
) it behaved perfectly.
When it came back from a test-flight, the pump was running continuously. Well, by 'continuously' I mean on/off/on/off roughly 2 times a second. Swapping the relay didn't cure it (but taking the relay out stops it), or the error code, but you can hear the relay being clicking off and AlfaDiag showed that the pump activations count was going up - so I presume something it telling it to do this.
After a little bit more testing, the selespeed system started behaving even more erratically - jumping back to neutral then going completely haywire (sounded like it was selecting gears randomly), which only disconnecting the battery would stop.
The relay seems to be ok, and I can't seen any chaffed wires going to it. I had a good look at a length of the loom and all looked ok.
So, I can only think that it's either temperature or battery related. Mike and I have suggested to Alan that a new battery would be the best thing to try. The car seems to be charging ok, so I don't think it's the alternator.
Hope you get home ok, Alan! Good seeing you again
I think we're almost there
PS All other fault codes have cleared. Car got belts, variator, water pump and TDC sensor today. And guess who only realised that he hadn't refitted the rear belt cover until it was time to fit the front one???
Don't think I'll make that mistake again