'05 Boxster battery drain after head unit install......

[Heaveho]

Hi, as title. Even with the head unit and amp fuses removed, my smart charger seems to need to input 0.2 amps constantly since the head unit was replaced. I'm now assuming that the MOST fibre optic loop is at fault and that the old CD changer or telephone interface is constantly live and has become an issue? Are there separate fuses for the telephone and cd changer?