If the brakes have been changed then i would suspect the .. er .. rather cheap mechanic changed the brakes but not the sensor wires .
What you have there is a bypass .. wires twisted together makes the car think the pads are fine .. on a normal sensor then as the pads wear it cuts through the wires , when an open circuit happens you get the brake warning light on .
Btw .. when you remove the caliper on these undo the screws that hold the pipe to the upright arm , allen key and a Torx at the top from memory .... pretty obvious but as i'm here already .....
What you have there is a bypass .. wires twisted together makes the car think the pads are fine .. on a normal sensor then as the pads wear it cuts through the wires , when an open circuit happens you get the brake warning light on .
Btw .. when you remove the caliper on these undo the screws that hold the pipe to the upright arm , allen key and a Torx at the top from memory .... pretty obvious but as i'm here already .....