Headlight adjuster/motor fault?

[preecy]

One of my headlight adjusters seems to have gone crazy, it's constantly adjusting and the motor is going nuts. I've had to disconnect it for now but have an MOT booked next week. Someone mentioned theres a sensor somewhere at the back of the car which contorllers these adjusters... can anyone shed any light on where it is and what im looking for. If its not the sensor, how much will a new adjuster cost me?

 

[Black Phoenix]

Please follow this topic. I just had inserted some photos.

http://www.cliosport.net/forum/showthread.php?304457-Xenon-motor-keeps-on-adjusting