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Gene Larew

alternator issue? new to boating

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Hello, new to boating.  1st time out with a 2006 Chap 210SSI 5.0 Merc 160 hrs.  Dual batteries with the 1/2/both/off switch system.  Started fine and idled fine—-out of marina and when any throttle given, the dash battery gauge jumps around erratically and the boat loses power.  If I then back off on the throttle , down to barely in gear) it would run fine.  I tried switching from batt 2–batt2-both and the same problem.  After 15 min of this, it finally shut off and would not even attempt to start-totally dead.   I got a tow into my slip and when I hooked up the on board charger at the dock and turned the key I had power.  Any ideas?  Thanks for the help in advance

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First thing I would do. Clean and check all the connections to the batteries and the battery switch. Even at the alternator and its belt. After that, use a meter and check the voltage with the engine off and running. With the engine running, you should read about 13.8 to 14.3 volts. If not, thats a problem. Engine off, you should be reading about 13 volts.  

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17 minutes ago, Gene Larew said:

Thanks.  Check these readings at the battery terminals?  or at another site?   

At the battery, but if your cables are corroded and if you do take a reading at both you will see a voltage drop. Thats why you need to clean and check the battery switch and its cables. Also there are You Tube videos how to do this on a car. Its the same thing! 

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alternator is an easy check use a voltmeter the batteries should be at 12 volts start the motor you should be getting 14.5 or 15 volts if not the alternator is probably shot 

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Could be 2 totally wornout batteries.  Could be Sulphated plates. They can only hold a little % of power.

If you switched from 1 battery to the other while running ?  Can sometimes damage electronic parts if the switch is the old style of............BREAK contact completely. Then......MAKE contact completely. A high voltage from the alternator can occur while  NEITHER battery is connected.  SWITCH only with a stopped engine.

Have you checked the amount of water in each cell of both batteries ?  If no water was maintained by other owners ?  2 permanently weak / RUINED batteries..............Borrow a GOOD STRONG battery. Put it in place of # 1 battery. That will be proof positive of bad battery.

TEST  TEST before buying.

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Nobody said the boat wasn’t tested.  I am looking for constructive help and advice from those who know more than me about boats, not assumptive criticism.  

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31 minutes ago, Gene Larew said:

Nobody said the boat wasn’t tested.  I am looking for constructive help and advice from those who know more than me about boats, not assumptive criticism.  

You need to forgive, he does this to everyone and he does not mean it.

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Sounds like an intermittent problem ... loose or shorted connection somewhere?

Switches, ignition key, buss bar, etc ... chasing electrical gremlins is not fun.

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I chacked as many connections as I could reach.  Pulled batteries and had them tested, they were 8 years old and had bad cells.  Changed both of them and when I run the boat in my slip it idles fine..12.6v engine off 14.6 engine on (testing at the battery)  When i run it with the “throttle only button” depressed it does fine for a minute until I give it more gas—-It then emits a “beep-beep-beep warning.  Temperature 175, oil pressure 40psi and jumps to 50psi before the warning.  As soon as I back off the throttle it runs fine.   Any ideas?  Is it OK to test like this in “throttle only”

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54 minutes ago, Gene Larew said:

I chacked as many connections as I could reach.  Pulled batteries and had them tested, they were 8 years old and had bad cells.  Changed both of them and when I run the boat in my slip it idles fine..12.6v engine off 14.6 engine on (testing at the battery)  When i run it with the “throttle only button” depressed it does fine for a minute until I give it more gas—-It then emits a “beep-beep-beep warning.  Temperature 175, oil pressure 40psi and jumps to 50psi before the warning.  As soon as I back off the throttle it runs fine.   Any ideas?  Is it OK to test like this in “throttle only”

The engine alarm sounds like it may be unrelated to your battery problem. Ideally you'll want to get a Mercury engine scanner plugged in to it, that will tell you what the problem is same as an OBD II scanner on a car. You may be able to find a chart online that will give you an idea of what the problem is based on the number of beeps.

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It is ok to test like that, for short periods, to rev the engine up a bit.

When was the last time you had your impellers changed?

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Had a similar problem with a friends 5.7 Merc. It turned out to be the round gang plug atop the engine, as the master positive prong was molded in shorter than the others in the gang. I spread the split prong, and forced it back in. Problem solved. Send me a pm with a valid e-mail address and I will send you a PDF file with the cliff-notes on Merc engine alarms and how to identify what specific malfunction is actually setting the alarm.  W

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Dude, I have no friggin clue what you just said.  I put people to sleep for a living and that is just not something I am familiar with.  I appreciate the help but I am gonna have to call someone on that business.  Why did I buy a boat?   F-Me

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Wow....  If this causes you such anger, sell it now. Boats are frustrating sometime. Hire a mechanic to look at it and show him Wingnuts post.. More times than not he is spot on... 

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People are too sensitive.  I said I don’t know why I bought a boat.  That is a typical joke.........get it.......again, like I said I will defer to a professional....Sheesh

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2 hours ago, Gene Larew said:

People are too sensitive.  I said I don’t know why I bought a boat. ...

You said a whole lot more ... misunderstanding perhaps ...

5 hours ago, Gene Larew said:

Dude, I have no friggin clue what you just said.  I put people to sleep for a living and that is just not something I am familiar with.  I appreciate the help but I am gonna have to call someone on that business.  Why did I buy a boat?   F-Me

As said, boats and the required maintenance can be frustrating, especially if one is not technically inclined. The 10+ year old boat requires a lot of attention even if it was well maintained which might not be the case here. The 8 year old batteries with bad cells onboard is a clue.

Start with replacing the old batteries with a new set, then start chasing those engine error codes yourself or with professional help but that might get really costly quickly  ... or reevaluate your new hobby all together. If you decide to proceed and keep your boat, the group on this forum is a top notch ... Wingnut, Shep, and many other are always willing to help if you are willing to listen. Good luck!

 

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The reason I asked about impellers was that I have seen the engine throw the warning beeps for an over rev warning when revving just the engine using the "throttle only button" which was caused by a failing impeller.

Obviously you bought the boat used.  Did you buy it private party or from a dealer?  Either way, a good relationship with a good dealer and mechanic is a requirement for boating.  There are a lot of things one can do themselves, but there are some things you just have to have a good boat mechanic look at.  I could change impellers myself, for example, but given how hard they are to do on the Merc 496 in my hull, and the parts you have to remove just to get to them, I leave that to my mechanic and it is money well spent lol!

Boats can really make you scratch you head.  Just remember, (B)reak (O)ut (A)nother (T)housand is not just a catchy phrase, it has roots in reality.

Diagnosing engine issues can be a real test in patience.  But it sounds like you can reliably reproduce it by revving the engine, so should be easy for a good mechanic to reproduce immediately and it is a good bet they will know immediately what is wrong.

Given the battery issues, it might we well worth it to have the whole boat go through a thorough preventative maintenance check, have the impellers changed, fluids replaced, charging system checked, etc.  Maybe this has already been done.  

I cannot speak for any other dealers or mechanics and what they charge for annual service.  I only know what mine charges, which include all of the above as well as alignment check, seals/gimbal, trim, trim tabs, throttle and steering cable checked, etc.  Basically checking every system on the boat to make sure they are working and to find any issues before they leave stuck out on the water.

After 8 years of year round boating and annual service, this years list was long:  trim tab actuators, drive trim sending unit, fuel sending unit, new batteries (every 3 years here usually with our heat), impellers, bilge pump replacement, oil change, gear oil change, and a few more things.

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