1988 150 blk max charging system

[Dead Eye]

Installed the battery in the boat today. The battery was fully charged 12.45 volts on the tester. I ran the motor on muffs,checked the voltage and it still showed 12.45 volts. Should the tester show more than 12.45 when the motor is running? Or because the battery has a full charge in it the charging system doesn't have to send extra [charging] power to the battery? <br /> Thanks, Dead Eye

 

[Dead Eye]

Re: 1988 150 blk max charging system

P.S.: I dont have the merc manual for 1988 only have 1990 and above. [bought by mistake]. Will my current 1990 merc manual show me the charging system for my 1988 motor problem?<br /> Thanks, Dead Eye

 

[Dead Eye]

Re: 1988 150 blk max charging system

^

 

[LubeDude]

Re: 1988 150 blk max charging system

I dont know for sure, but I dont think you will get much more than that at an Idle, try raising the RPMs a bit and testing it, not too much though on the muffs.

 

[Dead Eye]

Re: 1988 150 blk max charging system

I uped the rpms to just over 1500 and no change on the volt meter<br /> Dead Eye

 

[Dead Eye]

Re: 1988 150 blk max charging system

^

 

[Barnacle_Bill]

Re: 1988 150 blk max charging system

Check your rectifier using the book you have. They should be the same.