there is no rear tweeter .if front drivers tweeter is working then sound must be getting to the door so sounds like bass speaker is u/s or wire come off. same for rear door.i assume left front tweeter ok? .so its probably faulty speakers but you will need door trim off to confirm.rear ones be carefull top strip doesnt tear off door trim when removing. or alternately can you confirm continuity at head unit ?
Yes, left front tweeter is fine. No, I cannot confirm continuity at the head unit. I've got two options, get another ISO lead to convert for a Sony head unit, or get another head unit, OEM or DAB. But I don't want to spend the money on another head unit if the speakers are the problem. Is there a guide to removing door trim front and rear? The top of the trim is lose on both front doors, so I assume, somebody has had them off at some point. Possibly in relation to the speakers?