Re: 470 voltage regulator proper wiring?
Ah...the old water cooled 3.7L voltage regulator. First did this voltage regulator charge correctly wired this way? If so it is dead, although there are tests you can perform that are outlined in the Mercruiser manual - well worth the $30.<br /><br />The 470 (3.7L) voltage regulator should have four points of connection. Looking at it face-on, there is one connection on the left (middle) and three on the right (top, middle and bottom). The left connector and middle-right connector should have yellow-red leads, these are the two wires going to the stator. If you have an ohm meter, check resistance between these two leads (while dissconnected from the regulator. If resistance exceeds 1 ohm the stator needs replacement. Also check resistence between each of the yellow-red connection studs and teh regulator case with an ohm meter, replace the regulator if either reading is near zero. The top right connection should have a red-purple lead and the bottom right connection which is the regulator output, should have an orange lead (sometimes red/white like yours). <br /><br />If the output wire touches ground as you suggest, it will blow the regulator. The excess voltage gets dumped as heat, hence the need for a water cooled regulator. since the stator type charging system was usually combined with a closed cooling system, over heating worsened the situation of a poorly designed charging system. The OEM regulator is very expensive ($400), and since its inception subject to failure. Even when working correctly ths charging system was barely adequate for supplying the proper amount of charging needed for running and battery charging. The best bet is to replace the system with one of the many alternator conversion kits, although there are some new and improved regulators on the market, like this one.<br /><br />
http://www.breezeworks.net/ <br /><br />I replaced my old system with an alternator conversion kit 3 years ago after many stator/regulator problems, and the only regret I have is that I didn't do it years earlier. You can buy a complete conversion kit for under $400, NO NEED TO PAY MORE, and it installs in about an hour or a little longer if you're the cautious type like me. Just get the right one if you have power steering (alternator will need to mount on lower left front of engine), also check for "old" or "new" style harmonic balancer.<br /><br />In addition to Breezeworks (above) which has lots of 470/3.7L parts, here's other sites with 470/3.7L alternator conversion kits:<br /><br />
http://www.marineparts.com/partspages/Merc/merc25.htm <br />
http://www.amarket.com/imdc60.htm <br /><br />If you're inquisitive do a google search on '3.7L alternator' or '470 alternator conversion' etc. You find that the very same conversion kits will range from $369 to over $500. Remember no need to spend more than $400 for the whole fix.<br /><br />Good luck, hope things work out well.
