intermittent charging problem

[lrburke]

I know there are a bunch of posts about charging problems but just couldn't seem to narrow my problem from them! I have a 1981 GS550L and when I start it cold it charges over 13 volts at the battery. After the bike runs for several minutes the rectifier gets really hot and suddenly it no longer charges. After it cools off a little it will be charging again. This bike still has the loop going to the headlight switch and back to the rectifier. I have replaced all the bullet connectors with new and the ground is clean and tight! The rectifier fails the diode test everytime but it still charges at times. How do you eliminate the loop and do you think the rectifier is the cause? Battery is brand new also! Let me know if you need any more info! By the way I also tested the stator output with the bike at 5000 rpm's like the stator papers said and all three legs are strong at about 75 AC volts each

[posplayr]

I know there are a bunch of posts about charging problems but just couldn't seem to narrow my problem from them! I have a 1981 GS550L and when I start it cold it charges over 13 volts at the battery. After the bike runs for several minutes the rectifier gets really hot and suddenly it no longer charges. After it cools off a little it will be charging again. This bike still has the loop going to the headlight switch and back to the rectifier. I have replaced all the bullet connectors with new and the ground is clean and tight! The rectifier fails the diode test everytime but it still charges at times. How do you eliminate the loop and do you think the rectifier is the cause? Battery is brand new also! Let me know if you need any more info! By the way I also tested the stator output with the bike at 5000 rpm's like the stator papers said and all three legs are strong at about 75 AC volts each

http://www.thegsresources.com/_forum/showthread.php?t=152769

[BassCliff]

Hi,

To eliminate the headlight switch loop, just connect the three stator output wires directly to the three r/r input wires. I left my headlight switch wired disconnected and just cut them back and taped them off. See my website for pictures and more info. See Mr. posplayr's excellent guides (in his sig) for total charging system health.

It certainly sounds to me like you need a new r/r unit.


Thank you for your indulgence,

BassCliff

[tom203]

I'd review the gs charging system's health info , but it sounds like your r/r is bad. For reference, I have 1981 gs 650 with an OEM r/r. After an hour of riding ( with lights on ), I can put my hand on the r/r- it's warm, but not bad. Double check connections and make sure you have a good ground from r/r to battery negative.

[lrburke]

I just went out and made a jumper wire to the battery negative to ground the rectifier and it still did the same thing. It charged a perfect 13.2 to 13.4 volts at idle for about 5 minutes and after the rectifier got really hot I actually watched the voltmeter start to plummet really fast down to battery voltage.

[posplayr]

I just went out and made a jumper wire to the battery negative to ground the rectifier and it still did the same thing. It charged a perfect 13.2 to 13.4 volts at idle for about 5 minutes and after the rectifier got really hot I actually watched the voltmeter start to plummet really fast down to battery voltage.

Idle is not a very good test, but if you have a definite change like that (at higher RPM) as a function of temperature i would suspect the R/R first.