Only the front passenger door, it usually works if you leave the door open long enough say 15 secs. Guessing this is a sticky micro switch in the latch? Wondering if I whip the door card off can I free it off with a squirt of contact cleaner or has the latch got to come off to access?

Interior lights are controlled by the door ajar switch which is inside the latch itself. However, it is in a block of 3 switches that are rated at IP68 so other than giving it some exercise there's not a lot you can do as you can't squirt any contact cleaner into it.

I was hoping the switch plunger was just a bit sticky externally and binding on the switch body from dirt/grease and a 'wash' might fix it. Having never looked at a latch I don't know if this wash can be done in situ after removing the card and peeling back the water shedder. I'm reluctant to remove the latch at this stage.

No, you can't get at it with the latch in place. It's inside, you have to take the latch out and open it up.

Aww, bugger. Summer job then, Ta.
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