Alternator trouble.

[Uraijit]

As I mentioned in another thread, I've got a current draw on my batteries when the system is turned off.

As suggested, I installed a battery switch, and then went on to tracing out the culprit. Appears to be the alternator drawing about .28 amps of current.

I believe this is indicative of a bad diode, correct?

If so, is there a special "MARINE" diode, or can I just get the diode from Autozone, and call it good? I'm thinking that since the diode is sealed, it shouldn't be a problem. Am I right?

 

[Uraijit]

Re: Alternator trouble.

EDIT: I was wrong.

 

[Uraijit]

Re: Alternator trouble.

Okay, I just tore the alternator apart, and tested all the diodes. They all check out. What could be causing my alternator to draw .28 amps while everything is shut off?

It's a Motorola, if that makes and difference...

 

[Don S]

Re: Alternator trouble.

Take it to an starter/alternator shop and have it checked out properly. They can also fix it.

 

[Uraijit]

Re: Alternator trouble.

Can't seem to find anybody in my area who does it... I'm guessing Autozone's alternator test isn't going to show something like this.

Supposing I can actually find someone who will rebuild it, what's the average cost of a rebuild, VS just buying one from DB Electric for $60?

 

[Eliminator]

Re: Alternator trouble.

Motorola with the voltage reg on the back? I would think it's the voltage regulator. Does the drain go away when you disconnect the wire that turns on the voltage regulator? Yellow one if I recollect?

 

[Uraijit]

Re: Alternator trouble.

Don't know which wire that would be, someone spray-painted the alternator, so all the wires are black. Is this the wire I'm looking for?

 

[Don S]

Re: Alternator trouble.

http://www.arcomarine.com/xhtml/Tech Marine Alternator tips.pdf

Look at the top left on page 2

 

[Uraijit]

Re: Alternator trouble.

Alrighty, I went with my gut, and cut the red wire.

Sure enough, turned out to be the right wire, and the regulator was indeed what was causing the draw. I'm going to go ahead and order a new one tonight.

Is it going to be alright to use it until the new one arrives? Will it still charge the battery?

 

[Eliminator]

Re: Alternator trouble.

Hook the wire up and run it as long as it is not overcharging. When done for the day disconect the wire and all will be well!

 

[Uraijit]

Re: Alternator trouble.

Alright guys, I'm off to splash it again. Wish me luck!

 

[Eliminator]

Re: Alternator trouble.

Forgot to add! That wire to the reg should be switched or on with ignition switch on and off when off. If wires got switched somehow with hot all the time though your draw would be about 3 amps.

 

[Uraijit]

Re: Alternator trouble.

Yeah, nothing got switched, the draw just started happening one day.

Anyway, the boat's running great. However, after taking it out for about an hour, I checked the oil, and found it to be 2 quarts low AGAIN!

Thought re-sealing the timing cover gasket had fixed it. Traced it out to the oil pan gasket. Looks like during installation, we somehow managed to miss a screw hole on the gasket, and it's pushed clear in. There's about a 3/64 gap about 2" long that's spraying oil out pretty good.

Looks like I'm gonna have to go ahead and yank the engine out and re-seal the oil pan!

On the bright side, at least I'll be able to get the bilge nice and cleaned up from all this oil again...

 

[Eliminator]

Re: Alternator trouble.

you know when i really don't wan't something to leak I just dispence with the gaskets and use Permatex The Right Stuff or Locktite made the original and sold the name, don't remember what they called their's. Don't use too much as it squishes out but on equipment at work that runs 15 hours a day from minus 40 to 100 degrees I get about 7 years of not the slightest leak. things have to be clean when you put together like shot of brake kleen but I will use cork or composite gaskets on an oil pan if I plan on having to take it apart in the near future or it's a showy type of project not at work.

You know when I was young I had a beater dodge truck where the timing chain cover was spraying, Was planning to scrap it so dug out as much gasket from the leaking intake and timing cover, sprayed it down good with brake cleen and injected the cracks with the right stuff. drove it for another year and a half till I scrapped it!

 

[Uraijit]

Re: Alternator trouble.

Yeah, the trouble is that we pulled the oil pan off a couple of times during the build (don't ask). The 3rd time of pulling it off, I guess I got too hasty (the fact that there was already oil in it didn't help either).

I'm a big fan of Permatex as well, but it bit me in the butt the other day, when I used too much, and it squeezed out and partially blocked a water pump passage... I've generally had good luck with both cork and permatex, so I'll probably get a cork gasket, and seal it with permatex for good measure.

Thanks again for the help.

At this pace, I should have everything running great, in time to winterize it!

 

[Eliminator]

Re: Alternator trouble.

posting while I was posting! Save a season and do a spot repair till you can pull it over the winter? Personally I don't like permatex Silicone on cork but dont mind like locktite flange sealant on gaskets (intakes and water ports) as it won't solidify and block stuff.


You know when I was young I had a beater dodge truck where the timing chain cover was spraying, Was planning to scrap it so dug out as much gasket from the leaking intake and timing cover, sprayed it down good with brake cleen and injected the cracks with the right stuff. drove it for another year and a half till I scrapped it!

 

[Uraijit]

Re: Alternator trouble.

I've got an intimate knowledge of this boat and engine now. I can pull the engine in a matter of an hour.

23 min to seal the oil pan.

45 min to take it to the truck wash, and spray out the bilge/ski locker of all the oily residue

Another hour-point-five to put it back in.

We won't be losing the season due to an oil pan gasket. I was just commenting on how this project just seems to be taking all summer to get it running reliably... This setback is fairly minor, considering some of the other possibilities of what COULD HAVE been wrong.

I can live with this one.


EDIT: Oh, and I just remembered, I have a tube of REALLY good oil pan sealant. It's the stuff that Audi, VW, et al use to seal their oil pans (no gaskets for them).

Still got 3/4 of a tube left over from an oil pan replacement I did years ago, when I was still turning wrenches. I've used it on motorcycles with excellent results. I think I'll give it a shot for this oil pan.