fused

Hello first and foremost I'm looking for a way in which I can get switched power so my headunit turns off with the key. At the moment my accessory wire on my headunit runs straight to the battery with an inline fuse, this results in the there being constant power and the head unit always...

W124 E280 estate- was using lighter socket to inflate trailer tyres- used it for too long and fuse blew- when I replace fuse it instantly fuses again- clearly I have done a mischief to lighter socket but now my Parrot handsfree wont work- any easy fix to remove lighter socket or disconnect it...