Help please!

[6x6TRex]

What is this? What does it do? Do I need it? It is connected between one ac terminal and the dc terminal on the voltage rectifier. The motor is an 86 Merc 150 Blackmax outboard with an 87 Mariner 150 powerhead on it. It is bad (it looks like it exploded) and I think it is causing my overcharging problem from my other post. http://forums.iboats.com/showthread.php?t=326686
Also I don think I had one of these on my Merc, I have all of the parts from it but this! So can I just leave it off and just use the rectifier without it?

 

[j_martin]

Re: Help please!

What is this? What does it do? Do I need it? It is connected between one ac terminal and the dc terminal on the voltage rectifier. The motor is an 86 Merc 150 Blackmax outboard with an 87 Mariner 150 powerhead on it. It is bad (it looks like it exploded) and I think it is causing my overcharging problem from my other post. http://forums.iboats.com/showthread.php?t=326686
Also I don think I had one of these on my Merc, I have all of the parts from it but this! So can I just leave it off and just use the rectifier without it?

That is the shunt regulator. When it fails, the full unregulated output of the rectifier is absorbed by the battery and any load on the battery, such as lights.

That said, it is about as usefull as teets on a boar. A battery in good condition will regulate the voltage just as well. It'll use a little water doing it. The secret is regular maintainance on the battery. If the battery is allowed to go dry, the voltage will go up and probably wipe out lights or electronics on yer boat.

If you insist, you can use a shunt regulator off an off road vehicle, like an atv. A better way to regulate it is to replace the rectifier with a mercury regulator module, like one of the pair on a 40 amp system. It'll work just fine in that application. Just takes a little finageling to make it fit.

hope it helps
John