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Marky-mark
06-03-2012, 02:40 AM
:confused: I have a 2006 X2. This has me baffled - I found my battery would not hold charge. As it is 4 or 5 years old I replaced it this week. But I have noticed that there is a current drain from the battery when the isolator is left on. I connected my charger to the battery and the ammeter reads under half an amp for the new battery as I would expect. But the current drain goes up to about an amp when I turn on the isolator. This may not be the current drain without the charger connected but I dont have an ammeter to put in series - but it proves the drain is there. Everything in the boat works fine and nothing is left switched on. My first thought was a sticking bilge pump switch but neither pump is running and they both work fine normally. This isn't a major head ache at the minute as I can just turn the isolator off when I'm not using the boat - but I'm concerned that this may be the start of something more serious. Any thoughts???

JimN
06-03-2012, 07:46 AM
Use an ammeter- it's the only way you're going to find the cause. If you see about 300mA, it's most likely the bridge rectifier in the alternator.

Skyskiguy
06-03-2012, 12:56 PM
My guess is the alternator. My 92 PS205 had the same problem several years ago. After sitting for a few weeks, dead battery. Bad alternator was drawing it down. Had it rebuilt and problem solved.

Marky-mark
06-03-2012, 05:06 PM
I'll check out the current draw as soon as I can. Does that mean a diode has failed and is leaking to earth? In the mean time, if the bridge rectifier is at fault will this cause any other problems using the boat? I'm due away on holiday with the boat for a week soon and don't want it to fail. Not sure I could get the alternator rebuilt in time though.

JimN
06-03-2012, 07:07 PM
I'll check out the current draw as soon as I can. Does that mean a diode has failed and is leaking to earth? In the mean time, if the bridge rectifier is at fault will this cause any other problems using the boat? I'm due away on holiday with the boat for a week soon and don't want it to fail. Not sure I could get the alternator rebuilt in time though.

Don't just run off and have the alternator rebuilt- check for the source of the draw. The rectifier can cause problems if the DC voltage fluctuates a lot because it can't do it's job, which is to make DC out of AC voltage. Microprocessors HATE dirty voltage.

mikeg205
06-03-2012, 07:38 PM
Hi Jim...

Check out this video - if the alternator bridge rectifier was bad would it make the noise like on this video?

http://www.youtube.com/watch?v=7PIR-lWGV6U

JimN
06-03-2012, 09:07 PM
Hi Jim...

Check out this video - if the alternator bridge rectifier was bad would it make the noise like on this video?

http://www.youtube.com/watch?v=7PIR-lWGV6U

I have never heard an alternator make that particular sound when the rectifier was bad. It usually shorts internally and that causes the battery to discharge but that test bypassed the regulator and his tester wasn't able to handle the load, so I'm not sure if that test is as valid as when a shop puts it on a "growler" that can handle any load thrown at it. OTOH, a growler makes that sound because the alternator has problems, anyway.

The easiest test is with an ammeter. If the draw is about the number I mentioned and it goes away when the alternator is disconnected, it's the alternator. I wouldn't recommend using test leads to do what he did without making sure of where the leads have to go..

mikeg205
06-03-2012, 09:32 PM
Thanks - I have the same issue...the PO of the boat had it checked (95 TBI 5.7) by MC dealer in Iowa, but could not trace down issue of discharge...so PO installed a kill switch...Battery does not discharge anymore and I don't have any issues. But I will get an amp meter and check the draw this winter....

JimN
06-03-2012, 09:38 PM
Thanks - I have the same issue...the PO of the boat had it checked (95 TBI 5.7) by MC dealer in Iowa, but could not trace down issue of discharge...so PO installed a kill switch...Battery does not discharge anymore and I don't have any issues. But I will get an amp meter and check the draw this winter....

That dealer needs to send their techs to training. A current draw issue is about the easiest thing to find- you put the meter between the battery cable and terminal, measure the draw and start pulling fuses until it goes away. Did they think the freaking boat was going to tell them where the problem is?

If you have a regular test light with a bulb, you can do the same thing. If you see the bulb light up, it will go dark when you find the problem. For the alternator, you would remove the charging lead to make it go away.

Skyskiguy
06-03-2012, 10:16 PM
Mine was a bad diode in the alternator. Also, at one point, I found that I had a power amplified radio antenna that was wired directly to a hot lead, instead of through the ignition.

mikeg205
06-04-2012, 06:52 PM
Okay - OCD MC kicked and could not leave well enough alone and found that alternator was training my battery as well...when I disconnected it my current draw went from 125ma...which I know isn't a lot...to 25ma. But to my horror the alternator was not marinized....:mad: - I really don't like putting people in harms way....so I shot off a quick email to ask PO if he ever had it changed...he wasn't a DIY guy so someone did it for him...scary...

anyway... found these 2

#1

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=RPS7465PS_0232630281 - 55 amp

#2
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=RPS12176A_0245791033 - 65 amp..

I believe #2 is not marinized...#1 is the one I want...right?

Old alternator open and pictured

mikeg205
06-07-2012, 10:41 PM
Thanks OP and JimN...ran the boat today and new alternator kicking out 14.5 volts. Current draw with everything off now - just clock running is about 25 mA.

sooo happy...no more battery drain!!!! Yes!!