Yanmar alternator

[robonurse]

The alternator in my 2006 Yanmar 315 in my Albin 28 always delayed a few minutes after starting before it showed a charging state on the voltmeter. When I inquired about that, the term "excite the regulator" was used and I was told that it takes a few minutes for that to happen after starting the engine. Recently (when I winterized) I noticed that upon starting the engine, the voltmeter immediately went to a charging state. It appears to be putting out about 14 volts but I will check it with a voltmeter in the spring. Can any of you electrically saavy folks out there advise if I may need to have the regulator replaced? Also, early last season when I launched, it did not appear to be charging at all but later seemed to work fine and then was fine all season.

[Carl]

I think it is possible that what you are seeing in terms of the volt meter is, when you first start your engine cold, there is an electric air pre-heater that runs for up to 5 minutes. It draws considerable amperage and pulls your voltage down to sometimes below 12v. You should notice that after the pre-heater goes off, that your volt meter will slowly clime up to the normal 14v. Check it out and see if thats what your seeing. I will often sit in the slip and wait for the voltage to go up before leaving and useing the bow thruster. If I dont and the preheater is still running while useing the bowthruster, my electronics dosnt like it. Once it goes off there are no issues.

[robonurse]

Thanks, Carl but I don't think it is related to the pre heater. I can watch the gauge jump when the pre heater turns off before I even start the engine. I've had the boat since new and it is acting distinctly different.

[mhanna]

I do not believe the air heater turns off until after the engine has been running and the water temp reaches 100 degrees or so.
Getting back to the alternator, you can take it to almost any starter rebuilding place and they can run it on a bench test

[robonurse]

Thanks. That seems like the only reasonable course of action at this time. I'll plan to pull out the alternator as soon as the weather warms up a bit and get it checked out. Thanks.

[robonurse]

The alternator on my 31TE with Yanmar 440 shows no charging volts. After much diagnostic work and an alternator rebuild, it now bench tests fine but still shows no charge when installed. I found the air heater controller relay to be stuck (it actually had a burn hole in the controller) and the heaters were on constantly. Once I disabled the heaters, the voltmeter read normally. There was considerable rust in the plug and two prongs broke when I removed the controller. Since I only use the boat from mid April to mid October I am considering leaving the air heaters disabled, It seems to warm up and run fine without them. Has anyone had a similar experience or do you have any thoughts on this?

[catalina_mike]

I had my alternator rebuild locally and they put in a heavier duty voltage regulator regulator in it.

[jmfernan]

The alternator on my 31TE with Yanmar 440 shows no charging volts. After much diagnostic work and an alternator rebuild, it now bench tests fine but still shows no charge when installed. I found the air heater controller relay to be stuck (it actually had a burn hole in the controller) and the heaters were on constantly. Once I disabled the heaters, the voltmeter read normally. There was considerable rust in the plug and two prongs broke when I removed the controller. Since I only use the boat from mid April to mid October I am considering leaving the air heaters disabled, It seems to warm up and run fine without them. Has anyone had a similar experience or do you have any thoughts on this?

I disconnected the air heater on my 6LY 370. No change in smoke at startup (very little both with and without heater). Much less belt dust than before and don't need to tighten belt anywhere near as often.

[Serenity]

I had my heaters replaced 2 years ago. The yard disconnected the wiring and use brass or bronze plugs to replace where the heaters screwed into the holes on my 315. I also replaced my alternator. The local guy wanted $125 for a rebuild as oppose to one on-line for $95.00. All is good except the weather here on Long Island.