Why did my voltage regulators burn out??

[Chris1956]

Folks, I just acquired a 1993 Merc 135 HP V6. It has the dual 20A voltage regulators, fed from the 4 yellow wire stator. When I got it one V/R was burned out. I had it afew days and the other V/R burned out.

I can replace them, but I sure would like to know why they burned out.

 

[Laddies]

Re: Why did my voltage regulators burn out??

Most regulators burn out because of a voltage spike, loose or corroded connection in the circuit, in this case maybe 1 side of the system overloaded may have caused it or maybe some of Mercurys finer stuff.

 

[j_martin]

Re: Why did my voltage regulators burn out??

Because they're murkery regulators. Replace them with rapair/CDI.

hope it helps
John

 

[Chris1956]

Re: Why did my voltage regulators burn out??

Hey John, Are they just bad and fail whenever they feel like it? Is the CDI not going to burn out. At $200+ a pair, I want these to last.

 

[j_martin]

Re: Why did my voltage regulators burn out??

I really don't see any way for the durned things to burn out unless your electrical system draws a constant 40 amps or so, or you battery has a shorted cell in it. Even then, they should just go flat, and not burn.

The Merc regulators have a reputation for being weak. The CDI units are cheaper and also have a better reputation. If the stator were open, it would not charge. If it were shorted, it would self destruct.

New regs, clean up the connections, all is good.

hope it helps
john

 

[Silvertip]

Re: Why did my voltage regulators burn out??

Does the boat have a dual battery switch? If it does, turning the switch off with the engine running will pop a regulator. Poor or intermittent battery cable connections can also cause this to happen.

 

[MercFan]

Re: Why did my voltage regulators burn out??

Wouldn't it be advisable to put a fuse in the circuit?

 

[Laddies]

Re: Why did my voltage regulators burn out??

A blown fuse would guarantee a voltage spike

 

[Chris1956]

Re: Why did my voltage regulators burn out??

The boat has a single battery (no switch) and no accessories. I was planning to run on the one good regulator since a 20A charging system is more than enough for me. Now I plan to replace both regulators with CDI units, clean up the connections and hope for the best.

 

[JustJason]

Re: Why did my voltage regulators burn out??

also... get rid of the wingnuts on your battery and use nylon lock nuts with washers instead.

 

[MercFan]

Re: Why did my voltage regulators burn out??

Ah! Thanks Laddies