Should the flap on a MK2 facelift estate lock when car is locked? Mine can be opened any time. 

Yes, it could be the actuator is full of water and has seized in the open position, or someone has snipped off the tangs on the actuator as it seized in the locked position but still looks closed unlike most you see with it left slightly open (when they have failed).

Lots of manufacturers use the same actuator which I notice does not have a drilling for a drain hole to let any water out which enters down the locking arm shaft, the ones I’ve taken apart are all full of rusty water.

Or the lead going to it is open circuit, more likely the former though.

easy job to sort?

p/n 3T0810773. The simplest replacement is to re-solder the new wires to the old ones. Check first if you have power at the wires when closing and opening.

3T0810773

See image above….I wonder how to edit my just posted tekst...

My fuel refill flap won't lock tightly shut when the central locking system is turned on. It can be closed and it's flush with the car body but it's very easy to open by simply pushing inwards on the flap to release it - regardless of how the central locking is configured. (It's faulty.)

 

My new battery drains more quickly than expected and I'm now wondering if the failed actuator and solenoid are causing a parasitic drain on my battery. I'm thinking of disconnecting the solenoid, as someone else suggested.

 

However, I want to find whether I'm getting a parasitic drain or not first by using the multimeter and fuse removal technique. I'd be grateful if anyone can tell me please which fuse needs to be checked in relation to the fuel refill flap actuator and solenoid. (Not sure if I used the right technical term?)