So I got a stupid question regarding the testing of my alternator. Page 368 of the service manual says to disconnect the alternator connector(A) and connect my meter as shown later on p.369 . The picture is pretty crappy in the manual. I think I got the correct connector split but which side of it should I probe first for voltage between the 3 legs at 4000rpm and then resistance shut off? I guessed the male side. One time I saw >41VAC between two legs right after I started the bike but after that I kept getting no reading between any pair of legs. None of the legs is grounded but all show as open/infinite resistance. I questioned my meter but a new battery seems to have fixed it up so the readings are stable and reasonable on known circuits. The pic showing the plug I probed is attached. These readings lead me to think the stator coils are defective but I hoped one of you guys could see where I might be making a mistake or concur with my diagnosis. And I hope I am wrong because the price for one looks pretty high.
Thanks,
Dave

 

Have you tried resistance readings on the other side of the connector, female side?

Ride on
Brewster

 

You want to probe the harness that leads into the engine-that's connected to the stator. Verify that your meter is good by testing a wall socket in the house-ac scale, please. Then check dc on battery. Sometimes it can be tricky to get a good stab with the leads so ensure that's connected during testing. Hope it's something simple.

 

I was hoping someone who has done this could tell me which connector was the right one. Guess I will have to open up the wiring harness enough to follow wires from the stator to the plug. I did try both sides of it and both had similar readings. Only sure way is to trace it out with no solid advice. I did check my wall outlet and MC battery which both had started giving crazy readings: reasons I decided on a new battery for my meter. Looks like a new stator runs over $400. My magna is also down with perpetual carb troubles. Dave is getting tired of old bike troubles and dreams of a new ride but needs a pay raise. Maybe next year I can actually decide between a brand new Indian Scout, DR650SE, or DRZ400SM. Still would be much cheaper to drop a couple thousand into the magna and klx250 doing some suspension upgrades and repair work. Reality is that a $500 repair to continue riding a 7 year old motorbike I love is not terribly expensive and a few more on a 21 year old bike that has the potential for another 20 years will be reasonable.

 

So I loosened up some wire ties and followed the alternator wires out and I did test the correct connector. And having spent a few minutes reading about it, I have decided to rewind my own stator assuming it is only burnt out as expected with open winding conductors. I am now wondering if my heated vest and gloves caused this to happen and whether altering my windings could prevent this by increasing the electrical power output. Not being an electrical engineer I will need to read a bit more on the subject but it looks like a larger gage of wire using the same number of turns per pole may do the trick.

 

Go ahead and pull the cover and inspect the stator for signs of distress/burning. That will give you a better idea of the damage. This may help:
STATOR REWIND

 

So the stator is out and resistance between the three plug blades still show infinite resistance but when I probe the connections at the stator itself they look OK. In the neighborhood of 1 ohm but my crappy meter shows .4-.5 when I touch the probes together so may 0.5 ohms phase to phase. Also no connection with the core from each of the three so it looks like my stator is fine but there is a problem in the yellow conductors elsewhere. But it appears to be isolated between the stator and the plug. Oh, and those two sneaky bolts hidden under the starter cover took a while to find. Sitting up high on my work stool in a slightly dark garage made seeing them difficult. In my younger days I would have probably broken something trying to force it apart. Came pretty easy once I found the two sneaky bastages.

 

Maybe I should look at the wiring schematics first, but enjoy taking stuff apart and seeing how it works. I had thought that one or more of the yellow wires going from the stator to the R/R was bad but now I am leaning towards the R/R being shot. I got a good probe connection to both ends of the yellow wires and never lost continuity while bending them around in many spots. Then I tested the rectifier circuit continuity per page 371 of the manual and think it fails because the manual states that the resistance in one direction should be low and 10X+ in the opposite direction. Being a knuckle dragging wrench turner it took me a while to realize that the range on the meter make a yuge difference. Turns out I had to be in the highest ohm range to even get a reading other than an "open" in one direction The other direction was "open". Anyone got anything useful to tell me? I am all ears. Electrons are not my cup of tea but I am willing to learn.
Per the manual.---*The resistance should be low in one direction and more than ten times as much in the other direction. If any two leads are low or high in both directions, the rectifier is defective and the regulator/rectifier must be replaced.---

 

If your meter has a 1k ohms range, try that. My service manual is for the KLX300 and earlier KLX250's. The schematic in it may be different than what you have.

Ride on
Brewster.................retired electron chaser

 

Main thing to verify when you get it back together would be to measure A/C voltage across each leg of the stator windings. That's where the 41v spec comes into play-if you see something close to this on each leg then it may be the R/R. The yellow wires from the stator go directly to the plug on the R/R so verify the continuity between the plugs. Verify that the white and brown wires on the R/R have 12v and that the black/yellow has continuity with ground terminal. If all that checks out it should be a faulty R/R.