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Help with Alternator/Battery Charging Issue


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Update: Thanks everyone for the suggestions. Since I am impatient, I had the boat pulled out again today and took a stab at some of your suggestions. The breaker on the motor wound up being tripped. I pushed it and heard a little click. Didn't really think it did anything, but when I put the boat in the water and fired it up I was getting 13.3v at the battery!!!! Wooohooo. I love quick and easy fixes. 

 

I ACCIDENTALLY CROSSED THE BATTERY TERMINALS for like 2 seconds a couple weeks ago when I reinstalled the battery. I have taken the boat out a couple times before this and noticed voltage is low, it hovers around 11.3 with nothing on except the boat. 

Last weekend I took my new to me 2001 Wakesetter out. While I was stopped I filled all three ballast and played the stereo a bit to show some family friends. Fired the boat up to leave and all systems freaked out gauges would bounce on and off, perfect pass would not turn on, stereo would not stay on and boat would not go over 10 mph. Figured I ran the battery too and I also fried the alternator.

I ordered a new alternator this week figuring I fried the diode when I crossed the terminals and installed today. Battery voltage resting was 12.3, turned the boat on and it dropped to 11.9. Ran the boat for 45 mins and voltage dropped about .3 by the time I got back to the dock. 

I proceeded to test the alternator, set my volt meter to 20 DCV. Put the positive on the positive of the alternator and grounded to a bolt. It read 18.45!!!!!!! This is a brand new alternator, how can the voltage regulator be bad?

If the voltage regulator is bad will it not send any charge to the battery? 

I am at a loss so any guesses/direction would be great. Motor is Monsoon 5.7 350

Edited by Roush611
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2 minutes ago, oldjeep said:

so when you saw 18 volts the battery was attached? Sounds like a bad cell in the battery from your description.

18v was at the alternator. Battery never read more than 11.9 volts

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3 minutes ago, oldjeep said:

sounds like battery is internally shorted. Try a different one.

Ok, I will go buy a new one tomorrow and try that. I actually had one today but returned it because the battery load tested ok.

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1 minute ago, Roush611 said:

Ok, I will go buy a new one tomorrow and try that. I actually had one today but returned it because the battery load tested ok.

or just use the one from your truck. A 2001 has Regular car type terminal connectors correct?

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2 hours ago, oldjeep said:

or just use the one from your truck. A 2001 has Regular car type terminal connectors correct?

Yea it has post terminals.

I did trickle charge the battery this week and it accepted a charge to 12.65v. Let it rest for a day and it settled in at 12.3. Which by my research is still low...

Edited by Roush611
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could be! I dont know that wiring schematic with any great detail, but there are typically a couple of main breakers on the engine somewhere. Not the first time ive seen them tripped when battery cables are crossed. They are the once with the red buttons with amperage printed on the button. 

 

That 18V at the alternator and battery voltage at the battery, seems to me that the alternator is not "seeing" the battery load. A tripped breaker, or even a fuse, seems logical. 

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22 minutes ago, MLA said:

could be! I dont know that wiring schematic with any great detail, but there are typically a couple of main breakers on the engine somewhere. Not the first time ive seen them tripped when battery cables are crossed. They are the once with the red buttons with amperage printed on the button. 

 

That 18V at the alternator and battery voltage at the battery, seems to me that the alternator is not "seeing" the battery load. A tripped breaker, or even a fuse, seems logical. 

The engine breaker disconnects the output of the perko from everything. Boat can't start if it is tripped. Or if you don't have a perko it is inline on the positive battery cable.

Edited by oldjeep
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1 hour ago, MadMan said:

Does your new alternator have a voltage sense terminal (mine does)?  If so, what voltage is present there?

This is the new alternator....

https://www.amazon.com/gp/aw/d/B0094JHH5O/ref=yo_ii_img?ie=UTF8&psc=1

I don't know if it has one or not...

2 hours ago, MLA said:

Tripped a breaker when you crossed the cable. 

This is what I thought as well, but I have no idea where the breaker on the motor is. I read something about it being under the air filter near the throttle body but I did not see anything when I looked yesterday. The other big breaker I know of is right behind the battery box and I completely forgot to check that one yesterday. My understanding with that one though is if it is tripped nothing at all will work, the motor won't even fire...

Edited by Roush611
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1 hour ago, MadMan said:

I believe it's the one labeled "REG" with the red wire. 

Ok, I will check it out this week. The boat is stored at the marina and it's quite a process pulling it out and getting it in the water.

So I will touch the red wire from the volt meter to that and ground the other one anywhere?

Edited by Roush611
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3 hours ago, oldjeep said:

The engine breaker disconnects the output of the perko from everything. Boat can't start if it is tripped. Or if you don't have a perko it is inline on the positive battery cable.

Again, I do not have an exact schematic, just offing some general suggestions. it may not be a breaker, but rather a fuse such as this, thats on the end of the alt cable at the starter. Same result as a tripped breaker.

1305191c_2.png

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I appreciate all the suggestions. The more the merrier. That way I can check all of the above when I get the boat out this week. It's $10 each time I have it pulled out so I want to make sure I can check as many things at one time as possible.

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9 minutes ago, Bill_AirJunky said:

Bump....OP needs to spell check new update in original post.

Thank you! Sorry, posting from my phone, plus being excited this issue is fixed is not a good combo. 

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