Stator Test

I have a 2007 DL 1000 V-Strom:

I followed the following process while checking the stator:

  1. Put multimeter to VAC
  2. Tested the three phases of the stator connector plugged into a new regulator

1 > 2

2 > 3

3 > 1

When revving the engine, the VAC coming through climbs to only about 11.3volts (!?!) The VAC coming in at idle is 10.83volts. I am pretty sure I have a bad stator. Please let me know the following:


Am I performing the correct test or should I be looking for a different issue (given the symptoms)?

Am I doing the stator test correctly?

Other symptoms:

Battery does not recharge

Tasks done to date:

Swap battery

Swap regulator/rectifier

Tested no-load stator (link)


Removed the stator cover and discovered that the permanent magnets have broken loose from the rotor (so new rotor on order)

Based on the results of the test, and inspection of the stator I think the test has been validated as the correct procedure.

2 Answers 2


Is the rotor on this alternator a permanent magnet or is it a coil? If its a coil it will need an excitation current for the alternator to work.

  • I was asking about the rotor. If the rotor is a coil you need to check that it has current flowing in it or you will not get adequate voltage in the stator where you measured it.
    – dave
    Commented Oct 16, 2014 at 22:53
  • I see, after reviewing the part list for the bike. I think the rotor is a permanent magnet, while the stator is a coil. Any chance you could update how to test the rotor current?
    – Tommie C.
    Commented Oct 17, 2014 at 0:29
  • If its a permanent magnet there is no rotor current and my suggestion does not apply.
    – dave
    Commented Oct 17, 2014 at 20:14
  • Good to know about the need between the current requirement of coils vs permanent magnets. After inspecting the area I noted broken magnets that had fallen off the rotor (so that needs replacing). Thanks for the insight.
    – Tommie C.
    Commented Nov 27, 2014 at 21:00

Testing Your Stator

There are three yellow wires that come from your stator. They come out of the left side crankshaft cover and route into your sprocket cover and out along the cast bottom portion of your frame on their way to your rectifier. They connect directly to the rectifier. You can disconnect them from the rectifier and test them with a multimeter. Your first test will be static. The engine is not running. Be sure to disconnect from the rectifier and not just try and pierce the wires with the multimeter end. They are special wires and insulated a bit more, these are one of the few wires on the motorcycle that carry AC current.

  • Static Test Set multimeter to ohms and test between all the leads in pairs. The reading 0.1 to 1.0 max resistance.

  • No Load Test Dynamic Test Set your multimeter to AC Volts and start the bike. It should be cold. Have a friend hold the RPM's at 5,000. Test between the leads. You should see more than 70V. If it's below that, you may need a new stator. I would replace, but I'll get to that later.

Testing Your Rectifier

Your rectifier has diodes in it. Diodes are one way valves for electricity, think of a reed valve in a two stroke in-take. Since this is a three-phase charging system you need diodes to join the AC current into a single output and convert to DC. I could get more detailed but I want to keep it simple.

  • Rectifier Resistance Test Using your multimeter set to ohms connect the multimeter to the ends of each of the diodes and check the resistance in both directions. You should have low resistance in one direction and higher in the opposite direction. Generally, you will want to see 5 - 40 ohms of resistance in the forward bias direction, and infinite resistance in the reverse bias direction.

  • Procedure Attach the black probe (-) of the meter to the ground side of the rectifier (black wires) and the red probe of the meter to each of the three contacts for the stator. Record the numbers. Then swap around the meter leads (red and black are swapped) and take the readings again. You have thus measured the ground side of the rectifier.

If you have lower resistance in both directions (5+ ohms) then you must replace it.. If you have infinite in both directions you will need to replace the rectifier.

I hope this gives you some troubleshooting tools to remediate your issue. Best of luck.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .