1990 100 merc regulator/rectifier bad?

[sloopjohnb]

my batter was not charging, at idle I check the battery votage... 12V

checked the voltage the disconnected the red wire leaving the voltage regulator (in hind site after reading some other posts I'm not sure if this was a good idea) and left the internal one connected). restarted the motor at idle and checked the voltage on the red terminal .. 4V

checked the voltage on the yellow (stator) wires 20VAC


reved the the engine to about 2K and check the voltage on the yellow (about 30-50 vac), checked the output on the red terminal 14.3 V.

not sure if this this indicates the regulator/rectifier is bad or should I be looking at something else?

any advice?

 

[Barnacle_Bill]

Re: 1990 100 merc regulator/rectifier bad?

Sounds like everything is working fine to me. Most outboards do not charge until you get the RPMs up a little so that is normal.

 

[sloopjohnb]

Re: 1990 100 merc regulator/rectifier bad?

ok hooked every thing back up. even at 2000 rpm i get less than 13 volts (cant remember exactly, but was highter than 12.5, less than 13...I should write these things down when I'm at the boat). at idle I get 12.3V. engine off. I get 12.3V

 

[ricksrster]

Re: 1990 100 merc regulator/rectifier bad?

Try a continutity test on your rectifier. Set your Ohm meter to Rx1000. Place red lead on ground and black lead on each of the Alternaor posts. You should show continuity. Now reverse the meter leads. Black to ground and red to wach alternator post. You should have no continuity..Now place the black lead to the Pos. post ( where the red wire attaches). Red lead to each of the alternator post and you should have continuity. Reverse the leads and you should show no continuity.

 

[sloopjohnb]

Re: 1990 100 merc regulator/rectifier bad?

I know the test you described will work for a rectifier, but will it work for an integrated regulator/rectifier?

PS it has a stator not an alternator

 

[ricksrster]

Re: 1990 100 merc regulator/rectifier bad?

Running the motor with the red wire disconected probably dammaged the regulator. Should be putting out 14.3v at higher revs.
PS the stator is an alternator. It prodces AC. The regulator/rectifier turns it into DC.

 

[sloopjohnb]

Re: 1990 100 merc regulator/rectifier bad?

thanks for the help. I don't knwo what happened, but everything is workign fine now