[jascha]

I had the same issue with my volvo that suddenly the boot refused to open up. I searched online and read that it is possible to open the boot if you lower the back seats and slide into the boot and remove the back panelling attached to the boot lid. What I had to do is find the white connector that has 4 black cables attached to it and to the two thicker cables apply 9v from a battery and this released the mechanism and opened the boot. I did test the microswitch which is hidden under the handle on the boot lid and that was fine. The problem with mine was the cabling and after testing for continuity between both the microswitch , the 4 pole connector attached to the boot and the other end of the cable which is another plastic connector with 6 black leads connected to it (found on the left hand side on the roof of the boot), it resulted that 2 cables were not conducting and had snapped. The point where they snapped was through the rubber pipe that connects the lid to the car on the left had side of the car. I resoldered the cables and all is good now.