24 hours having the cylinder head refurbished on my own Saab 93 1,8 Linear after a snapped timing belt ,the battery charging malfunction warning message came up on the screen. I removed the alternator and bench tested it ( I am a professional alternator/ starter repair engineer), replaced the regulator anyway and the fault went for about a week. The message came up again and I repeated the procedure only for the fault to come up again. I energised the alternator and it proved to be ok. Even with the warning message up, the alternator output remains spot-on. A couple of starts and a poke about and the fault goes for a while only to return. Error code 0621 shows (alternator warning lamp circuit). Has anybody out there got any idea where to look for an open circuit or indeed any fault pertaining to this problem?. Would a hard reset such as disconnecting the battery work? I stress that this is my own vehicle and the fault is intermittent. I'm at my wits end. Please help me all you kind Saab owners / engineers out there.