Charging Woes - Interpreting Stator Papers Results

[phillylightguy]

Hi everyone,

My '80 GS250T doesn't charge properly. There was a period of time when I would just put the battery on a charger every few rides and it did fine (lazy, I know), but that got less and less successful. Then it died on me one day, I pushed it home and it's been parked for about 6 months.

Today I finally found time to do the Stator Papers tests. Sometimes the readout on my multimeter just said URFKED. Is that a bad sign?

But seriously, here are my results. I'm a little wary because the results make it look like everything is the problem. That may very well be the case, but I'm hoping folks on here can double-check me on this.

Quick test:
1. Key off: 12.77V
2. Key on: 12.06
3. Idle: 12.12
4. 2500 RPM: 12.12
5. 5000 RPM: 12.14
6. Key off: 12.51 and slowly rising, I saw it get to 12.58

So, clearly no charging voltage.

Phase A
Step 1: See quick test, no dice.

Step 2: Battery + to red wire on R/R: 5.3V. Clearly way too high. This section of wiring measures 4-5 ohms, is that enough to cause that kind of voltage drop?

Step 3: Battery - to R/R black/white: -.61V. A little too high. Is it weird that it's negative?

Phase B
Resistance between pairs of stator wires (measured at connections to R/R): All three pairs around 1.5 ohms.
Resistance from stator wires to the engine case: All three wires reading at or near dead short.
Voltage between pairs of stator wires: Ranging from 31-43 VAC.
Voltage from stator wires to battery - terminal: 20, 25, 17 VAC

Phase C
Diode test, red test lead to red R/R lead, black to yellow R/R leads: All three reading OL.
Red test lead to black/white, black test lead to yellow leads: All three reading OL.
Switched to continuity test, reading no continuity anywhere. Checked all the wires.

SO, in conclusion: Wiring is bad, stator is bad, R/R is bad?? Any advice on what I should do next?

 

[posplayr]

Hi everyone,

My '80 GS250T doesn't charge properly. There was a period of time when I would just put the battery on a charger every few rides and it did fine (lazy, I know), but that got less and less successful. Then it died on me one day, I pushed it home and it's been parked for about 6 months.

Today I finally found time to do the Stator Papers tests. Sometimes the readout on my multimeter just said URFKED. Is that a bad sign?

But seriously, here are my results. I'm a little wary because the results make it look like everything is the problem. That may very well be the case, but I'm hoping folks on here can double-check me on this.

Quick test:
1. Key off: 12.77V
2. Key on: 12.06
3. Idle: 12.12
4. 2500 RPM: 12.12
5. 5000 RPM: 12.14
6. Key off: 12.51 and slowly rising, I saw it get to 12.58

So, clearly no charging voltage.

Phase A
Step 1: See quick test, no dice.

Step 2: Battery + to red wire on R/R: 5.3V. Clearly way too high. This section of wiring measures 4-5 ohms, is that enough to cause that kind of voltage drop?

Step 3: Battery - to R/R black/white: -.61V. A little too high. Is it weird that it's negative?

Phase B
Resistance between pairs of stator wires (measured at connections to R/R): All three pairs around 1.5 ohms.
Resistance from stator wires to the engine case: All three wires reading at or near dead short.
Voltage between pairs of stator wires: Ranging from 31-43 VAC.
Voltage from stator wires to battery - terminal: 20, 25, 17 VAC

Phase C
Diode test, red test lead to red R/R lead, black to yellow R/R leads: All three reading OL.
Red test lead to black/white, black test lead to yellow leads: All three reading OL.
Switched to continuity test, reading no continuity anywhere. Checked all the wires.

SO, in conclusion: Wiring is bad, stator is bad, R/R is bad?? Any advice on what I should do next?

Stator IS Bad!!

The resistance between Battery and R/R should be less than 0.1 ohms.
If yours is really 4-5 ohms then with the SHUNT R/R it will try and kill teh stator which looks like it succeeded. The R/R probably mortally wounded itself which is a good thing. Get a Series R/R like a SH775.

 

[phillylightguy]

Thanks, posplayr.

So I'm thinking the first thing I need to do is replace some wiring, including the fuse holder. What supplies do folks use for this? And if some of my (37-year-old) wiring is going bad, do I need to replace the whole harness at some point soon? (Which sounds like a big project.)

Should I rewind the stator? I believe it was replaced by the guy who had the bike before me, about 4 years ago, so physically it should be in OK shape.

 

[posplayr]

The most important connections for changing is anything between teh R/R and the battery. Generally everything can be cleaned and prepped to reduce further corrosion.
Sanding paper will not get it. The crimps get oxidized and heat up making it even worse.
You typically have to cut off the bullet connections at the stator and use quality spades or solder. (prefered)

http://www.thegsresources.com/_foru...ing-Electrical-Connenctions&highlight=Cleaner

http://www.thegsresources.com/_foru...-Charging-System-Health&p=1138531#post1138531


Good job on the testsing. The wiring clean up is not that that bad and do a SPG as described wit ha new R/R.

If you can rewind teh stator have a try at it. They are about $100 or find the guide here at the GSR.

 

[phillylightguy]

The most important connections for changing is anything between teh R/R and the battery. Generally everything can be cleaned and prepped to reduce further corrosion.
Sanding paper will not get it. The crimps get oxidized and heat up making it even worse.
You typically have to cut off the bullet connections at the stator and use quality spades or solder. (prefered)

http://www.thegsresources.com/_foru...ing-Electrical-Connenctions&highlight=Cleaner

http://www.thegsresources.com/_foru...-Charging-System-Health&p=1138531#post1138531


Good job on the testsing. The wiring clean up is not that that bad and do a SPG as described wit ha new R/R.

If you can rewind teh stator have a try at it. They are about $100 or find the guide here at the GSR.

Great, that makes sense. Thanks for your encouragement.