1989 115ETLF Overcharging

[Dilbeck]

The battery voltage rises to just over 16V when I am running. I thought it had to be the voltage regulator/rectifier so I replaced it but get the same result.

Also, my multigauge for fuel level, oil warning, etc. flashes from time to time and resets. I am wondering if I might have a grounding problem. I have tried to check all that out but have not found anything strange.

Are there special grounds I should be checking? Any other ideas?

[boats.net]

Check battery cable connections are clean and tight at battery and on engine, look for loose or corroded ground wires on engine.

[Dilbeck]

I have checked the battery cables and all are clean and tight. I even took sandpaper to them to be sure. I removed all the ground wires on the engine to inspect and clean. All were quite clean.

With engine running I monitored the voltage at the regulator as well as at the battery. Both were the same. That is, the voltage between the black and red wires on the regulator climbed above 16V. I also checked to see if there was voltage drop between the regulator and battery on both the ground and 12V side. There was less than 20 milivolts so that all seems OK.

I forgot to mention that I also have a T8 with electric start connected to the same battery. Could this be affecting it? I will remove it next and re-test.

This has me stumped!

[Dilbeck]

I disconnected the T8 to reduce the number of variables. The result was the same.....overcharging to over 16V at the battery.

Then, I remembered that I put a new battery in the boat this spring. Since I still had my 6-7 year old battery, I put it in the boat. Now the voltage never gets over about 14.1-14.2V. I suspect this is because the old battery is....well....old. A hydrometer test has it at the low end of the yellow scale.

So, I no longer am going over voltage but I don't believe this is a reasonable fix. The new battery tests out just fine on my smart battery charger.

Any ideas?

[99yam40]

what kind is the new battery?

Seems like I remember seeing something about do to use maintenance free batteries, but I could be wrong about that.

Try a different good battery and see if if makes any difference.

[cyrillefrenchy]

sometimes batteries looks good with the tester but they don't keep the charge or they don't accumulate the power, resulting in an overcharging voltage and sometimes frying the rectifier or the stator, the power goes nowhere.pretty common problem on newer yamaha vx 110 waverunners.
just try another battery
frenchy

[NoNameDk]

I disconnected the T8 to reduce the number of variables. The result was the same.....overcharging to over 16V at the battery.

Then, I remembered that I put a new battery in the boat this spring. Since I still had my 6-7 year old battery, I put it in the boat. Now the voltage never gets over about 14.1-14.2V. I suspect this is because the old battery is....well....old. A hydrometer test has it at the low end of the yellow scale.

So, I no longer am going over voltage but I don't believe this is a reasonable fix. The new battery tests out just fine on my smart battery charger.

Any ideas?

Hi, did you solve the problem? and how? I have similar problem, Br. Nicolai