Help i woke up this morning and my merc wouldnt start. when you put the key in the ignititon the dash lights go out and nothing happens, occasionaly the dash will light up and a message saying RESTRAINT SYSTEM VISIT WORKSHOP SRS but then it goes out and may not return for a while. this has only started happening this morning so ichecked the battery with an electrical tester and it was fine.can anybody shed some light on this please
