88 Johnson 150vro 12.5v where to begin?

71Windsor

Petty Officer 1st Class
Joined
Jun 25, 2008
Messages
286
im only getting 12.5v on the meter at a bump over idle what should i begin with to get it back up to oem charging specs? engine is depleating batteries on me after use with NO electronics just the engine it self. I thought 12.5 should be fair enough to trickle charge the battery and run a second batter for electronics but its not. are the regulators some how adjustable?


Thanks in advance.
Frank
Pennsville, NJ
 

Lou-cifer

Recruit
Joined
Aug 17, 2008
Messages
1
Re: 88 Johnson 150vro 12.5v where to begin?

Check for an external external regulator. Do a search on OMC VOLTAGE REGULATOR 35 AM

MarineEngine.com had a pretty good price - $ 100 less than the dealer (for my 1986 110)
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 88 Johnson 150vro 12.5v where to begin?

The engine only uses battery voltage only when it is starting or running the trim. The engine ignition runs completely on it's own power when running, so running it will not further deplete the battery. The voltage regulator/rectifier is device which charges the battery. When functioning properly, it should eventually cause the battery voltage to approach 13-13.5 volts. A good meter will show this. If the rectifier/regulator is not functioning properly, typcially, your tach will start acting up, as it also sends to signal to the tach.
 

71Windsor

Petty Officer 1st Class
Joined
Jun 25, 2008
Messages
286
Re: 88 Johnson 150vro 12.5v where to begin?

Well i do not have a tach. So i wont know that repsonse. And I thought 12.5 would be enough to just keep the batter fair. I do not usually have any instruments on and generally dont adjust my t/t often at all. Just to tilt to ramp then no wake then cruising trim and that will be it for the day.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 88 Johnson 150vro 12.5v where to begin?

12.5 is not even charging. A fully charged battery is 12.65 Volts. When underway, you should be at 13-13.5 volts as stated. If not, troubleshoot your charging system as per your manual.
 
Top