ZT-T/75 tourer tailgate lock problems

[PC2]

Evening

I did post this last week, but had no response, but I'm sure someone must have some more ideas of what I can check or even a remedy.
I have reached the end of my sanity trying to get the tailgate electronic switch working.
It worked intermittently when I bought the car last year (my third ZT-T - am I mad?) but stopped working completely about 6 months ago.
I have cleaned all the electrical contacts in the tailgate and check wiring for damage.
I have changed the plinth (in case the actual button switch was faulty).
I have now changed the locking mechanism (solenoid) in the tailgate.
I have disconnected the battery for 10 mins and reconnected.
I cannot see a fuse blown (is there a particular fuse I should check?)
I have tried holding remote buttons.
Nothing, it's dead, extinct, without life, expired.....but why?

Has anyone got any other ideas?
Are there some other connections worth checking?


It's a 2003 pre facelift model, low mileage, 190. I need help, please.
thanking you in advance

Paul