Will my boat blow up???

[caken]

Ok so here is the deal...

So I did a very stupid thing when changing my batteries and switched the negative and positive cables on my battery terminals (please do not laugh at me, I am a new boat owner). When I moved the switch to the battery that was backwards smoke started to come out of the alternator.

I switched the battery back to normal and fired the boat up. It ran fine and the voltage meter read 13 at 2,000 rpm.

I believe the alternator is working, but am concerned that maybe some of the plastic around the wires might have burned off. Is it safe to run the boat with the alternator the way it is? I do not know how much damage there is on the inside.

 

[TahoeQ4Pilot]

Re: Will my boat blow up???

I suggest the smoke you saw was a diode (or two). Certain electrical devices are designed to allow electricity to flow only one way, when something causes change like reversing the cables like you did, the diode is the protective device that blows.

I think its time to get a new alternator.

 

[caken]

Re: Will my boat blow up???

Thanks for the info. I think the alternator is still working. I plan on taking it in and having it rebuilt or changing it all together.

My concern is that I want to take it out today and need to know if it is safe or not. If it was one of the diodes could it potentially spark and be a safety hazard, or will it just short out the alternator and cause it to not charge?

 

[imperial200]

Re: Will my boat blow up???

worst case your alternator is shot and will not charge, you can rebuild an alternator for like 20.00 and it only takes like 20 mins i say just put on a new one before you go out. . .you dont want to get stuck out at sea

 

[bruceb58]

Re: Will my boat blow up???

the diode is the protective device that blows.

I think its time to get a new alternator.

I agree that you proabably blew one of the diodes in the diode bridge. Diodes do not serve a purpose as a protective device at all. Thie purpose is to rectify the AC output of the alternator into DC. If you have a diode or two blown, our alternator output may have more AC ripple on it. You can check how much ripple by measuring the output with your hand held meter set to the AC position. Not sure what the spec is for it but I am thinking it should be less than 0.25V.

 

[Bart Sr.]

Re: Will my boat blow up???

My concern is that I want to take it out today and need to know if it is safe or not. If it was one of the diodes could it potentially spark and be a safety hazard, or will it just short out the alternator and cause it to not charge?

If MY boat has ANYTHING not 100% and I know about it the boat goes NOWHERE until it is fixed.PERIOD.

Just thinking out loud.

 

[caken]

Re: Will my boat blow up???

Thanks for all the advice. I ended up finding a place open on Saturday and they rebuilt it in a few hours.

Definitely better than risking it. Thanks again!

 

[Chris1956]

Re: Will my boat blow up???

Caken, Just so you know, a bad diode can cause the entire alterntor to burn up. Sometimes diodes open and not allow current flow. Sometimes they short, and allow two way current flow. If that happens, current flows from the battery into the alternator coils and you can have a fire.

Also, sometimes the diodes short spontaneously. For example, I had just gotten my boat ready to go into the water. I had run the motor, checked everything and all was good. I shut off the motor, and was planing to get some fuel and launch it, when the alternator just started smoking. My guess is that a diode had suddenly shorted. I had to quickly disconnect the battery to stop the smoke.

 

[deadstick]

Re: Will my boat blow up???

smoke is what makes all electronics work. if you notice when the smoke comes out, electronics work no more.

 

[justchange]

Re: Will my boat blow up???

smoke is what makes all electronics work. if you notice when the smoke comes out, electronics work no more.

That'd be correct.