What would cause this stator to fail?

[ddaum]

Just looking for some simple insight.

1980 Suzuki GS 550L

I am VERY familiar with the Stator Papers. A few years ago I went trough my electrical from front to back. Cleaned/preserved, etc. I replaced the stock stator (was failed) and r/r with Electrosport and Rick's respectively. Everything wired correctly with quality connections. Check out was good, the bike ran and charged fine for a few years up to now. I recently went back through the connections and grounds after I had the battery die on me. I am meticulous at this. Got a new battery. Charged it up. Did the "Stator Papers" check to find that all is well EXCEPT one phase of output is like 3.5 volts while the others are over 60. So it seems my stator is toast again, but I can't help but wonder why? What would cause this? I keep my GS in tip top shape, the best i can. I don't ride hard, I have no electrical accessories, no corrosion or bad grounds, quality/clean connectors. I just don't want to buy and install another stator and/or R&R only to have it fail again in the future.

I DO have a switched headlight. I heard there might be an unnecessary wire to the switch from the stator, but I need more info on this. Currently, my stator is wired directly to the R&R.

With the one bad lead, I can still get a low charge to the battery with the headlight off, but when it gets turned on, the voltage on the battery will continue to slowly drop. At 5000rpm it seems to hold about 12.1V with the headlight on, but drops off when rpm is lowered.

I'm at my wit's end because I KNOW all my connections are good. I know the fuse box is solid and clean. I know there are no rouge voltage drops. And ALL checks in the Stator Papers pass except that one phase of the stator only producing 3.5V.

Do I just suck it up and buy a new stator?
Where is this "list" of compatible Honda R&R units?
Should I go ahead and install the fused wire from the red R&R wire directly to the Battery(+) during this repair?
Where is this wire loop to the headlight switch if my stator is wired directly to he R&R?

Sorry for all the questions, any advice and/or links to information on the above modifications would be great.

[BassCliff]

Hi,

Do I just suck it up and buy a new stator?

At this point you don't have much choice.

Where is this "list" of compatible Honda R&R units?

I have a copy on my website HERE.

Should I go ahead and install the fused wire from the red R&R wire directly to the Battery(+) during this repair?

I did this the last time I replaced my r/r unit. My latest r/r unit (from a newer CBR something) has 2 output (red) wires and 2 ground (green) wires. I have one red wire going into the harness and the other going through a fuse directly to the battery (+). I have one ground wire connected directly to the negative battery terminal and the other connected to a common frame ground.

Where is this wire loop to the headlight switch if my stator is wired directly to he R&R?

You can probably see it in your wiring diagram. One leg of the stator is connected through the headlight switch. It can be a source of extra resistance. But if all three of your stator outputs are wired directly to the three inputs of your r/r unit, then that loop has already been disconnected. I've got a picture or two in this Regulator/Rectifier Replacement guide.

It could be that a failing r/r unit caused your stator to run too hot, melting the windings and disabling that leg of the stator. It happens. I went through three stators before I finally got everything cleaned up enough and wired correctly. Everything seems stable now. (Knock on wood.)

Measure the voltage drop between the r/r output and the battery positive terminal. There should be 0.2v or less. If you run your r/r output directly to the battery then I guess you don't have to worry about this measurement.


Thank you for your indulgence,

BassCliff

[OldVet66]

The aftermarket stator you got was a quality part. The R/R was in the same league as the stock R/R, prone to the same failures. The wiring through the headlight switch was to cut off one leg of the stator so it wouldn't fry the stator with the light off. That's how bad they were. There are more reliable R/R's out there. Personally I prefer the Compufire system. It switches off instead of shunting to ground when charging is not needed, therefore running cooler. It doesn't heat the stator as much so the oil in turn is cooler. It's down side is it's cost, but in the long run, batteries, bulbs and stators will last a lot longer, so maybe it is the cheapest solution after all.