hello again, had no internet for last few days...
it turned out to be the driver's side motor which i've simply unhooked from the mechanism. as a result i now have no central locking, but to be honest i'm not really bothered. it's less to go wrong again plus i'll easy get used to letting passengers in. will maybe try a bit of oil or a fresh motor at some point but i'm happy for now!
been a huge help as always, thanks a lot