Is it ever OK to see smoke coming from the alternator ...

[shemandr]

Today I hooked up the batteries in order to test some gauge circuits. No shore power. Battery switch one "1". The ignition switch was not on but it had been when I tested a switch. I never tried to crank the engine. I heard what sounded like water trickling a saw a small plume of smoke. Not enough for me to smell anything like burning wiring. I quickly disconnected the batteries and there was no more smoke. The alternator did not feel hot to the touch. Anyone have an idea of what happened? Do alternators get re-builds?

 

[kappykaplan]

I can only answer one of your questions. Yes, alternators can be rebuilt.

 

[Roadking Larry]

Any leakage of the all important magic smoke from electrical and electronic components is bad juju and the reason needs to be identified and rectified most rikky-tic.

 

[shemandr]

To continue my query, I hear about burning out diodes. If that happened are they replaceable? Anyway the alternator has to come off. Boat's on the hard by the way.

 

[Maine Sail]

Sounds like the batteries are / were possibly hooked up backwards..??

Really need a lot more detail on this to better help..

 

[Rich Stidger]

Every electrical item I know of only works well when the smoke is contained. Once the smoke is allowed to escape, despite no observance of fire or flame, the device will be dead or damaged.
Seriously, I would pull the alternator and get it tested. I hope you did double and triple check the battery hook-up. You didn't make the common mistake of reverse polarity did you?

 

[justsomeguy]

Poor or corroded connections can cause smoke, FWIW.

 

[shemandr]

Because I didn't put the boat away last fall due to a family health problem. The yard put it away and didn't disconnect the negatives. So I don't think I could have reversed the polarity. It is possible I put the positives on the wrong batteries because they were just laying near the respective batteries.

 

[Jim 5757]

Either I'm losing it (or maybe I lost it already???) but it sounds like something's missing here. Your not explaining why you think the alternator has a problem. If it IS the problem, I'm with Maine Sail...

 

[tipsyravensailing]

i'm thinking a few pictures might help? there might not be a bunch about sail power i know of but i've been rebuilding cars since i was a preteen - smoking alts might be a rectifier problem or a voltage limiter problem. Even if the battery was backwards the diodes should have stood off the power unless they were bad. Granted you do horrible things to the battery doing that

There's usually a window on the alternator, i find near the back, that lets you look down inside the rectifier if its internal. older might have an external unit that has to be hooked up. anyways, in there you can see the pins that lets you get a volt meter on it and do a diode test.

either way you can get the alternator off the boat and to a local auto parts place - there's not many that don't have an automatic alternator test bed. You'll want it off either way to test/replace etc.

once the magic blue smoke is let free the genie no longer makes the mystery bits inside keep working. Given that i'm reading that the leading cause of boat loss is fire and that the leading cause of fires is electrical it might be time to replace anyway.

 

[shemandr]

I took the alternator off the boat today. I decided that last night. I called a rebuild place that is in Southhampton. A bit of a drive for me. On the way I stopped at Larry's Lighthouse Marine and walked out with a new one - same everything. I have to do some wiring improvements before installing but I hope by Wednesday PM it will be in. Can't test it until mid-May when hopefully I get splashed.
The guy at Larry's said he thinks it got wet. The boat was covered all winter but maybe.
I hope these photos help - I've not looked at them yet.

 

[tipsyravensailing]

Corrosion is resistance. Resistance is amps. Too many amps and alternator browns out...

 

[shemandr]

The first photo is the switch I replaced which started all this.

 

[Meriachee]

That’s some pretty rust there. Might want to take care of that before something really does fry.

 

[Maine Sail]

You'd be wise to find that leak before installing the new alternator..

 

[Gene S]

OMG. Wet and rusty.

 

[pateco]

OMG. Wet and rusty.

You just described my whole engine LOL

 

[dziedzicmj]

Every electrical item I know of only works well when the smoke is contained. Once the smoke is allowed to escape, despite no observance of fire or flame, the device will be dead or damaged.

unless you manage to put the smoke back in

 

[tipsyravensailing]

The switch may have failed due to the increased load due to the resistance of corrosion. There may be additional corrosive problems elsewhere in the elctrical if the alternator terminals are any indicator. The switch is rated for only so many amps. Rarely do you see a switch die from "use" - almost always due to load.

When replacing, use a dilectric 'goo' to seal up the connection so water cannot penetrate and cause the same problem. They sell boots for alternator studs that would help keep things mitigated, definitely if you packed it with that stuff first. You might have to replace the alternator due to the smoke but i'd also go one step further and make sure connections stay high and dry or are properly treated to prevent future issues.

really, the big one to remember - where there's smoke, there's fire.

edit: https://www.globalindustrial.com/p/...MI94rmzrrT2gIVwySBCh1arA4kEAQYAiABEgKqvvD_BwE

something like that.

 

[oldlaxer1]

unless you manage to put the smoke back in

I'm not aware of anyone who has successfully reinstalled the smoke without considerable expense.