Here's a bit of info for all, the door light with the grab handle (also known as a coast light) on my van went faulty, stayed on all the time even when you attempted to switch it off(went off then came on by itself). I unscrewed it and disconnected it so as not to flatten the battery and found that water was getting through the light, at first I thought it was the rubber seal but found it got through the join(light is in two sections), the wood took a day to surface dry so don't know of deeper water damage. Anyway to cut a huge story short I would advise all to check if this is happening to you. A good indication is the bottom two screws will be discoloured
Goanna
Goanna
