Overcharging - 80 XS stock system - Christmas tree lights

[glennpd]

I have a 80XS which had a bad rotor. With the old rotorit would not charge at all. I installed a new (used) rotor with 5 Ohms across the slip rings. It no longer has a bad rotor but is now overcharging. It produces 16+ volts at 1000RPM. My Taillight warning light (Red one) never extinguishes and my Headlight warning/charging system warning light never extinguishes. I have swapped safety relays and reserve lighting units. It makes no difference.

I suspect it is the regulator but at this point I can not be sure. It is installed on the bike and as you know it is nasty to access on a stock bike. If I had a spare I could plug and unplug to see if that works, but I have no spare.

Does anyone have any suggestions?

Thanks

Glenn

 

[DogBunny]

You have a bad voltage regulator.

 

[retiredgentleman]

The regulator may or may not be faulty. If a regulator loses either the voltage reference or the ground connection, then it will try to give maximum voltage output, such as +16 volts. Check that you have a good ground connection to the regulator.

 

[DogBunny]

Yeah, actually I meant to say that "your voltage regulator is not working." Whether due to a bad regulator or a bad connection...

 

[glennpd]

What is the procedure to check for ground at the regulator? Does the mounting of the regulator provide ground?

 

[hmusket]

IIRC the 1980 model is the combo rec/reg and does ground when mounted to the frame.

 

[gggGary]

IIRC The regulator controls the ground brush on an 80 It's possible the lead is shorted to ground somewhere or you inadvertantly grounded the inner brush somehow. Do not run it this way, high chance of that high voltage frying other components.

My personal feeling is that a lot of charging sytem failures go back to owners trying to run bikes with bad batteries. The charging systems are overworked trying to charge an unchargeable battery, eventually something else overheats and fails.

 

[glennpd]

Yes, I checked ground at the regulator body and it is excellent. I checked ground at the black wire from the regulator and it too was good. Just for sh*ts and grins, I checked ground fron each of my brushes and both show ground. That does not sound right. The stator and brush holder are the late model type which does not ground the brushes to the stator. When I disconnect the connector from the staator to the loom, both brushes are at infinity. Sounds like the regulator is shorted to ground.

 

[glennpd]

Ok, went to Napa and Radio Shack today. Building the PamcoPete recommended rectifier and regulator. I am going to vary slightly from the example layout. Rather than putting all parts on the same plane, I will be bendint the aluminum 90 degrees at the edge of the regulator. So the bridges will be mounted parallel to the frame and the regulator perpendicular.