I have a 1989 4.3l mercruiser. The alternator is bad but I cant make out any of the numbers except that it is a 55amp unit. It has a purple and a red wire coming off the alternator and two studs for a ground and a red wire. It also looks like it has an external voltage regulator. This is a NONSERPENTINE unit. Any suggestions <br /><br /><br />Thanks <br /><br />AL