1981 70hp Charging problems

[Sliver]

Hello friends,

I have a 1981 70hp Johnson that runs great but I am not getting anything as far as charging voltage goes. 12.65 at battery both engine off and at idle up to 1500 or so. I'm not exactly sure of the stator/rectifier relationship so a brief summary would be good to hear. I performed the rectifier test outlined in another post and it failed. No continuity in either direction on 2 of 3 wires and continuity on 1 wire in both directions. Being as the rectifier is a fairly cheap item I plan to replace it. Should I be looking further up the system also? I gather that basically the rectifier converts the AC from the stator to DC to the system, am I correct and any other thoughts to get my voltage up? Your kind help is greatly appreciated.

 

[Barnacle_Bill]

Re: 1981 70hp Charging problems

A new rectifier should fix it. All it takes is a little spark or batt cables hooked up backwards just for an instant to blow them

 

[Sliver]

Re: 1981 70hp Charging problems

Thanks bhile, I have one on the way. Am I correct with the relationship between the 2?

 

[jammer]

Re: 1981 70hp Charging problems

Add in there. I personally got a new rectifier..which it might have needed...but the magnets on my flywheel were missing. I, in trying to make sure everyone gets as most help that they can...put the rectifier in..test the voltages..it should be fine..but if not..then I would post again. Also you can tell if the rectifier isn't working by the tach not working if you have one.

 

[Sliver]

Re: 1981 70hp Charging problems

Thanks Jammer,

No Tach but I will test after the new rectifier and post results. I really appreciate this forum.

 

[Sliver]

Re: 1981 70hp Charging problems

To all who responded. Thanks. New rectifier in, I was kind of expecting instant results but the voltmeter started out right at battery level. After running awhile it slowly crept up. I ran it for about 5 minutes and it showed 13.3 volts. I'm happy to see anything above battery level. Is it normal to take awhile to get up voltage? I plan to check it out on the water after running higher rpms for a day. Thanks again.

 

[Seasport]

Re: 1981 70hp Charging problems

Should be OK. The battery was probably a little flat which meant you got a lower reading.