'81 Johnson not charging battery?

[BB79RANCH]

I own an '81 Johnson 50 h.p. outboard and after changing the stator which included both the sensor coil & charge coil, used but good rectifier along with new ignition coils, then checking all above components with ohm meter to see if all compnents were within spec. All pieces tested good, but I am still having a problem with the charging system. The outboard will start very quickly, even when cold, and it runs pretty good though I do have another problem not related to the charging system (I hope). Once started I used a digital ohm/volt meter to see if unit is charging, at battery I have 12.0 volts and at red lead of rectifier I have 12.0 volts, none of the other three wires coming from the rectifier has a positive voltage on them (as I was checking rectifier it's case felt hot to me, is it supposed to be?) . Does this outboard have to attain a certain RPM for charging system to work or do I need to replace components. Like I stated earlier all readings were in spec. (the ones I could get by using an ohm/volt meter). Please help I don't want to get stranded in the middle of a lake not to mention the Gulf of Mexico.<br /><br /> Sincerely,<br /> Todd Tedder

 

[12Footer]

Re: '81 Johnson not charging battery?

I don't know for sure, but if anything, the regulator is bad,or the battery is not accepting the charge.<br />But one thing you can try is, run the battery down a bit (less than full charge),and quicly take another reading at the battery. It should be 13.8 VDC or higher,and drop to 12VDC when fully charged.<br />Just a guess on my part tho. If I were sure it would not damage the regulator or diodes, i would disconnect the terminal and check it to ground...But no way without the shop manual and some study first. Many charging circuits will fry when you do this.

 

[BB79RANCH]

Re: '81 Johnson not charging battery?

Thanks 12Footer for the reply. Where would the regulator be on this engine? Working on outboards is new to me, just want to be careful on what I do so as to not create bigger problems while trying to solve another.<br /><br /><br /> Thanks again,<br /> Todd Tedder

 

[clanton]

Re: '81 Johnson not charging battery?

NO regulator, only stator and rectifier. IF the rectifier was getting hot with engine running, I would think the stator was doing something, cant find my book on this engine, but meter should be on AC function to read stator output and then it will read low, and DC function to read rectifier output.

 

[BB79RANCH]

Re: '81 Johnson not charging battery?

Thanks Clanton, <br /> I don't remember seeing any other electrical parts dealing with this engine other than the stator, rectifier, power pack and ignition coils but that doesn't mean there aren't any more pieces that I may have overlooked. I have a Seloc manual for this engine and to say the very least IT SUCKS. Almost every section that deals with model & year of my outboard is very vague in this manual. It skims over the top on alot of issues where I need a bit more detail especially in the electrical/synchronization chapters.<br /><br /> Thanks again,<br /> Todd Tedder<br /> I appreciate all the help that this board affords me.