Poor charging with headlight on

[mborzillo]

HI, I've followed several posts regarding the rectifier/regulator. I'm suspecting this is the problem. I did a quick check without headlight and I'm charging about 14v at 4000 rpm. I turn the headlight on and I get about 11v. Should I still suspect r/r? I have recently had the faring off to repair it and had the first problem with drained battery about 3 weeks later. Any chance I may have goobered something up reconnecting things?
thanks
Mark
1979 GS850, 24K miles, running strong

[bonanzadave]

Might as well do the cheap stuff first.

1. Read the Stator Papers - free
2. Visually inspect - free (fusebox, headlight bucket, wire harness and connectors.)
3. Contact cleaner - $5 (disconnect, inspect, spray clean and reconnect all the electrical connectors)

Thats all I had to do to fix my charging problems.
After that you may need to spend some $. Id suggest an onboard voltmeter. Mine is on full time so I always have an eye on the charging system.

[Guest]

I second bonanzadave.

on my 3 bikes, I have eliminated charging problems on all of them by tracking down voltage drops between the RR and battery. (one of the first things the stator papers ask you to do)

[Guest]

Stator Papers

[Dave8338]

Clean all your contacts / connections first...cured the issue that I had with low output voltage. All grounds bullet connectors, every thing. Pay special attention to the R/R I removed mine from the bike to detail it and give a good look over and when reinstalled, everything works perfectly. Luck, maybe...don't think so.

[PB_Maine]

Stator

I ended up needing a stator. ATo test it, I disconnected the 3 wires from the stator and measured the voltage between each with the engine @ 5000 RPM. The 3 should be fairly balanced. Mine were like 70V,70V,55V (that's right, so don't test it with your tongue) and the imbalance was enough to keep it from charging with the headlight on. If you need one look for the brand reccommended in the stator papers, it's cheaper than Suzuki's and I believe it's just as good.
The job wasn't as big a deal as you would think. The difficult part for non electrical people is the testing, just read the stator papers, get a manual and take your time.

Anyway I hope its something cheaper like a loose connection.

[mborzillo]

Thanks for your inputs. I had checked the stator and all looked good. I'm pretty confident it's putting out, especially since my lights brighten when I rev it. I'll hunt down any poor connections or grounds, and thanks for the copy of the Stator Papers.
Mark