1999 ox66 225 flashing 12 volts

[family affair]

Both batteries are new. Running one battery shows 12.4 volts at idle and when the RPM's increase so does the voltage. When running the other battery the yamaha display shows 12-12.2 volts. When RPM's increase/ voltage does not. Also when running on this battery, it will occasionally flash 12V on the display.
Any ideas?

 

[ctcbtr]

swap batteries and see if the problem stays the same or goes to the other side

 

[1st grady]

Thats ironic because the same happened to me this weekend. Two new cranking batteries installed 1 month ago. I did not get time to take multimeter measurements but prior to installing them they were fully charged. Usually while running they show around 14 volts. My motors started and ran fine otherwise. I will let you know what I find but I will need to wait till next weekend. I have 2003 HPDI 150hp. I will start by reversing the battery switches 1,2. Check the actual voltage with a meter.

 

[family affair]

What does the flashing voltage mean on the Yamaha display?
I don't think I have ever seen 14v on the display. I wonder if I have a charging issue.

 

[seasick]

Both batteries are new. Running one battery shows 12.4 volts at idle and when the RPM's increase so does the voltage. When running the other battery the yamaha display shows 12-12.2 volts. When RPM's increase/ voltage does not. Also when running on this battery, it will occasionally flash 12V on the display.
Any ideas?

Two questions:
Does the motor start on each battery ?
On the battery that shows voltage increase as revs go up, what voltage does it show? It should get to 13.5 or higher at about 1200 rpm depending on the charge state of the battery.

The flashing voltage display is an alarm indicating low voltage.

Oops, one more questio: Did you recently remove or disconnect your batteries? If so, you may have missed a ground connection on one of the batteries.

 

[family affair]

Yes the engine starts on either battery without issue. We did this several times. I did not try starting on the "both" setting.

I'm not sure how high the voltage went up. I'll need to look again, but I don't think it hit 13.5 @1200.

We did remove the batteries and reinstall them. We bought the boat last fall and when we had the boat out it was doing something similar. We checked the wiring of the batteries to the recommendations of the manual, so I don't think that is the issue. We replaced the batteries because they were old and we suspected the issue was the batteries. I'm starting to think it is something else.

 

[seasick]

Very strange. Is there a cable connecting the two negative terminals of thebatteries together?
When switched to the battery that has the issue, do other devives work, like the radio, bilge pump, lights etc?

 

[family affair]

Yes there is a wire connecting the 2 negative terminals.

The gps and radio worked when we switched to the other battery. We didn't try any other elctronics.

The batteries we took out last fall tested bad. We replaced one with a new one to enable us to do testing and set-up new electronics over the winter. That battery died within one month. We replaced this battery with another. Same brand and same model. This replacement is the one giving us an issue.
My Dad was out with me when we had the issue described at the beginning of this thread. He said the good battery (the one not showing low voltage) would go up to 14 volts when RPM's increased. We are wondering if the manufacturer had a bad run of batteries and we just happen to get 2 duds. If so, great quality control!

I hope this makes sense. Tough to type when a 4 and 2 year old won't let you think clearly for 30 seconds! :bang

 

[seasick]

Yes there is a wire connecting the 2 negative terminals.

The gps and radio worked when we switched to the other battery. We didn't try any other elctronics.

The batteries we took out last fall tested bad. We replaced one with a new one to enable us to do testing and set-up new electronics over the winter. That battery died within one month. We replaced this battery with another. Same brand and same model. This replacement is the one giving us an issue.
My Dad was out with me when we had the issue described at the beginning of this thread. He said the good battery (the one not showing low voltage) would go up to 14 volts when RPM's increased. We are wondering if the manufacturer had a bad run of batteries and we just happen to get 2 duds. If so, great quality control!

I hope this makes sense. Tough to type when a 4 and 2 year old won't let you think clearly for 30 seconds! :bang

I suppose there is a possibility of a bad battery but I can't understand how that would cause your symptoms. If it were bad, I wouldn't expect it to start the motor. If one cell were completely shorted out, it might start but the voltage would read about 10 volts. In other words, I am stumped.
I don't remember if you answered this but have you swapper the two batteries to see if the problem stays with the same battery. If it does, I would suspect the battery. If it doesn't I would suspect wiring.

 

[ahill]

My son had the same problem on his '99 250's. Battery would lose charge over a day of use with GPS & depthfinder. Other house battery was fine.
After checking charging circuits, which were normal, turned out to be a bad battery.

 

[family affair]

I don't remember if you answered this but have you swapper the two batteries to see if the problem stays with the same battery. If it does, I would suspect the battery. If it doesn't I would suspect wiring.

Not yet. It will be our next step.

My son had the same problem on his '99 250's. Battery would lose charge over a day of use with GPS & depthfinder. Other house battery was fine.
After checking charging circuits, which were normal, turned out to be a bad battery.

I hope it is this simple. If it is, I'm going to be concerned about the reliability of this model battery. I might need to look at a different model.

 

[family affair]

Self healing?
Batteries were swapped around. The problem seems to have gone away. Our best guess is that something goofy was happening because of a bad contact somewhere. We'll keep an eye on it and report back any new developments. Thanks for the feedback!

 

[family affair]

The problem does not seem to have gone away entirely.
After digging in the Yamaha manual we found a section that indicates something to the effect that if the wires coming from the alternator are wired in such a way with a dual battery set-up that voltage on one battery will be limited to prevent electronics from seeing too much juice. This would allow one to isolate the electronics by hard wiring them to the battery only getting a max voltage of ~12.6.
We can't confirm if the system is indeed wired this way bc the manual suggests talking to the dealer for the wiring diagram. Is anyone familiar with this set-up?