Zero Electrical

[Fixer]

Hi Everyone
Ive been loving my little 80 gs250t. I’ve done a bunch to it and it has been running great this year.
Here’s my situation. I was out for a ride the other day, cruising along, maybe a gear up to run a bit quieter but nothing unusual. All of a sudden bike starts chugging, losing throttle power. I pull in the clutch, rev it a bit, bike dies flat. Hit the start button, nothing. Off I get, walk around the bike and there are no lights. Zero electrical power. I manage to bomb start it going down hill and it runs, not well, no lights. I limp it home, running, I can’t go over about third gear, bike starts chugging, still no lights.
I love troubleshooting. I check everything, main fuse, good, ignition, good, start button, good, battery, good. The only erroneous readings I find are off my regulator/rectifier. It’s a reactance check and I find no readings from the w/r wire or the y wire. I’m hoping I found my problem, just wondering if anyone has seen this issue. I’ve ordered the part and will keep this updated as to my findings. Two weeks for parts, gives me time to put some new tires on, maybe paint a few more bits. Thanks for your time, stay safe.

[Cipher]

Typical charging system failure symptoms.
Charge your battery fully then try the bike again. Barring bad connections if it runs fine for even a few minutes its very likely the reg/rect or the stator.

What price are you paying and is it oem you ordered? There are better possibly cheaper alternatives.

[Fixer]

Awesome
Cipher thanks for the reply.
When I checked the stator charging at the battery I had 14-15v, must be the regulator. Fingers crossed.
I’ve ordered one off amazon, aftermarket I think it was a bit less than $40 delivered. Slow delivery, I’ll update the thread once it comes in and I try it. Thanks for the advice, much appreciated. Nice to know I’m on the right track.

[Nessism]

If you had 14-15 volts DC at the battery then the regulator is fine. What did you order and why?

[Fixer]

Hi Ed
Thanks for the question.
When I checked the resistance on the regulator from the red wire to the w/r (lights) and the y (ac generator) I found no readings. I’ve ordered a new regulator/rectifier from amazon, a bit under $40 with delivery. What do you think?
Thanks for the help

[Fixer]

I should add
The bike will start and idle, with no electrical/lights if I jump a screwdriver across the starting solenoid.

[Rich82GS750TZ]

Fixer.
There are years of threads on this forum regarding the GS charging system and what to do to fix it. You can read mine, linked in my signature. My problem stated exactly the same as yours. Throwing OEM parts at it is not the way. You haven’t tested the output of the stator. If you can get the bike to run, disconnect 3 stator leads, do the quick test linked in my sig, also phase B test leg to leg and leg to ground.

[Fixer]

Rich
Would having 14-15v at the battery when running at 5000rpm not prove the output of the stator?
Thanks

[Rich82GS750TZ]

No. What proves the output of the stator is measuring the output or the stator.

[Fixer]

Thanks Rich
After checking the stator wires, w/b, w/r & y, they’re all open. I’m thinking this is a good indication that it’s smoked.
troubleshooting electrical is fun, I’m a mechanical guy. Very thankful for the help.
Fixer

[posplayr]

FYI

https://www.thegsresources.com/_forum/showthread.php?164993-Charging-System-QUICK-TEST

[Nessism]

If you are getting 14-15 VDC across the battery then the stator is FINE. Sounds like the charging system is fine...although 15V is a little high. 14.5 is a better number. It could be the regulator is not working to full capacity, and more times than not that's due to wire harness issues. And speaking of that, if your bike has one leg of the stator running though the hand control switch that should be bypassed. There are thousands of charging system posts here detailing what to do so no need to reinvent the wheel, just research a little.

[Fixer]

Thanks for all the reply’s. I’ve been reading all morning. Through everything so far, I’m wondering. I have no lights, when I turn the key to on. When I check the key switch, it all checks out, I do have power to the key switch and all contacts check out. It looks like w/r wire from the rr goes to the lighting switch. The other two rr wires go to the ac generator. Is having no lights a symptom of a bad rr? Also no power when I hit the start button. The only way I can run the bike is to bomb it or jump the poles on the start solenoid.
Electrical troubleshooting - days to find, minutes to fix.
Mechanical troubleshooting - minutes to find, days to fix
Going out to check/play some more. Thanks again

[Cipher]

http://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/GS250T-300LZ_manual-82.pdf

may be different 80 vs 82 but this is a nice resource

[Fixer]

So here’s the latest. I now have power when I turn the key, at least the bike will fire and idle when I push the start button. Also I can turn the high beam on, no low beam, faint brake light, and only the rear right signal goes on, and stays on lol. Some other strange findings. Voltage at my grounds. (Thanks for the tips) 1.9v except for when I disconnected and checked the ignitor ground and checked, 10v there. Good times, started raining here so time for a break and some reading. Cheers