Cooked Alternator

[Larry Jackel]

After 3 1/2 seasons and about 700 hours the factory installed Balmar 90-100 alternator (high output alterntor option) on my H44 died. A mechanic in Gloucester replaced its guts today those of a spare 912-100 that he happen to have and I am up and crusing again. The old unit looked overheated with an appearently melted wire near a lug connection, although the diodes ohmed out fine.

The Yanmar 4JH4E engine comes with a plastic fan belt shield that blocks airflow around the alternator. This sheild has deformed from heat. Today I used a Dremel tool to cut away the shield where it covered the alternator. Hopefully this mod will keep my rebuilt alternator from cooking again.

BTW ... the voltage regulator is a Xantrex Ideal Regulator Output Module on a Heart Interface Link 2000R, all factory installed.

A call to Balmar disclosed that the 90-100 model was discontinued in 2003, a least a year before my boat was built, so there may have been a design problem with it.

Has anyone else has problems with this alternator or discovered deforming of the fan belt shield?

Thanks!

 

[Jeff]

Not Yet

On our 2006 Hunter 45 CC we had a 100 amp Balmer installed about a year after we took delivery of the boat. We had the Hunter dealer to the install. A year later, only one problem, when the "max charge" regulator decided to go dead. A service call fixed that. I have seen the plastic guards on some of the newer yanmars, and always thought that it would be a good idea as far as safety goes, but maybe not now.

Jeff

 

[Landsend]

Check your batteries and your sensing wire on the voltage regulator.

if you have a bad battery on the sensing line is faulty, your alternator will overcharge, overheat and cook itself. Also check the sensing wire, as you may have fried a perfectly good alternator.

High output alternators do produce an awful lot of heat. I've installed a computer fan in addition to the alternator fan to help keep mine cool. I also have a fan that vents my engine compartment.

 

[ED]

alternator temp

Alternator temperature it the primary cause of alternator failure.
You can controll alternator temp with many external regulators. The Balmar A-5 with a battery and Alternator sensor (optional), Will sense high battery or alternator temps and reduce the output of the alternator, thus reducing the heat it produces.

This will make an alternator live a lot longer, especially in warm climates.

Im not sure if the type you have will do it, but it it will you should hook it up. If batterys get really low and the alternator has to run at high output for long hours it will reduce its output amperage to let it run cooler.

Mine works great.