Basic HiFi system. All functions in the head unit work. Front speakers all work. Rear door tweeters both work. No evidence of water leaking where the Amp is in the left rear compartment. Found a wrecked E53 with hiFi in the junkyard, swapped out that amp for mine, same thing no change. Main speakers in both rear doors are out. Has anyone encountered wiring issues? Seems unlikely both speakers blew out.