Originally Posted by
GraphiteGhost
Crawl under the rear of the car with a straight edge razor and slice a really thin cut through the middle of the passenger side rubber plug in that bulge (cavity if you were able to open the trunk and get down there) below the trunk opposite where the tire fix/jack storage is. There is (if I remember correctly) one rubber plug on each side. They are located close to the area where the rear axles/differential sits on the bottom. The one you want to check (first) for water in it is the passenger side. If you slice through that rubber plug, and water comes flowing out (you might have to spread that sliced rubber plug center), you found your problem. If it has been quite a while since it rained (or you washed the car which got a lot of water in there), the damage may still be there but not as obvious. Water intrusion into that well/cavity gets into the central security/locking module and it plays all he11 with things.
Water was in the well cavity. Drained water and used hose pipe to find leak. None found. I think it was probably a leak in the back window before the new top was put on in August. Installed part, Central Locking Pump module and everythng works except for the high beam headlights.Thank you for your help and also for saving me a lot of money!!.