evo classic sticky
Voltage Regulator?
Ultimate HDF Member
Joined: Jan 2013
Posts: 5,092
Likes: 2
From: Wenatchee, WA
A battery's decreased capacity will first be noticed when cold cranking IMO. I don't think this sounds like a battery problem - u were on the road so basically the battery is out of the picture. To keep the battery topped up the regulator/stator needs to keep about 14.5VDC on the grid. What happened in your case was that you had a power sag. Check the connections in to and out of the regulator. It is important that the regulator be properly grounded to perform properly.
Road Master
Joined: Jun 2010
Posts: 1,221
Likes: 4
From: Annemasse (border of Geneva-Switzerland) facing Mt-Blanc.
When you crank the engine the voltage should not drop below 9.6 Volts measured directly between the starter motor (+) lead and the frame; then directly across the battery terminals you should not find a difference greater than 0.5 Vdc.
Most "12V" starter motors are designed for a nominal voltage of 10 Volts under load and 15 seconds duty cycles. If you have more than 10 Volts on the starter motor leads while cranking you are not using its full power and if you have less than 10.5V on your battery terminals this means the battery doesn't deliver its full power because it has too much internal resistance.
When you have loose power connections (battery, frame or starter) the battery voltage stays high and the starter motor voltage goes low.
Last edited by Expat1; Jul 2, 2013 at 07:22 AM.
Road Master
Joined: Jun 2010
Posts: 1,221
Likes: 4
From: Annemasse (border of Geneva-Switzerland) facing Mt-Blanc.
What do you mean by infinity reading ?
Road Master
Joined: Jan 2008
Posts: 968
Likes: 11
From: Oconomowoc, Wisconsin
The reading between each pin and ground...
"With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace"
But I still get this...
" Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM"
Is my stator toast? or regulator??
I'm getting the correct AC voltage to the Regulator...but nothing more than 12v @ battery...
Can the stator still put out the correct voltage if it's shorted..??
Reason why I'm asking is.. I had the same readings before.. I had bought a new stator..but just for grins I replaced the regulator with one i had layin around... and it was charging again... that was 5-6000 miles ago..
So I have a new stator..but would rather have to replace the regulator seeing that it's a much easier job..
"With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace"
But I still get this...
" Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM"
Is my stator toast? or regulator??
I'm getting the correct AC voltage to the Regulator...but nothing more than 12v @ battery...
Can the stator still put out the correct voltage if it's shorted..??
Reason why I'm asking is.. I had the same readings before.. I had bought a new stator..but just for grins I replaced the regulator with one i had layin around... and it was charging again... that was 5-6000 miles ago..
So I have a new stator..but would rather have to replace the regulator seeing that it's a much easier job..
Last edited by kyote; Jul 11, 2013 at 09:26 AM.
Road Master
Joined: Jan 2008
Posts: 968
Likes: 11
From: Oconomowoc, Wisconsin
I know.. thats what I'm going by...
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Road Master
Joined: Jun 2010
Posts: 1,221
Likes: 4
From: Annemasse (border of Geneva-Switzerland) facing Mt-Blanc.
The reading between each pin and ground...
"With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace"
But I still get this...
" Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM"
Is my stator toast? or regulator??
I'm getting the correct AC voltage to the Regulator...but nothing more than 12v @ battery...
Can the stator still put out the correct voltage if it's shorted..??
"With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace"
But I still get this...
" Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM"
Is my stator toast? or regulator??
I'm getting the correct AC voltage to the Regulator...but nothing more than 12v @ battery...
Can the stator still put out the correct voltage if it's shorted..??
You always measure 2 sets of coils by connecting the voltmeter to wires AB AC BC.
These coils should never be related to ground that's why you look for the 'infinity' ohmic value.
When the engine runs and everything is disconnected you can read AC voltage between wires AB AC BC because we have a permanent magnet to produce the field.
Connect these 3 wires to the regulator and put a dummy load (bulb) on the 2 wire connector. Start the engine.
On the Bat+ and Bat- leads of the regulator look for presence of AC voltage (possible leak) coming from one or more diodes and measure the DC voltage.
Usually when your battery is capable of starting the engine and you can see your lights dim at idle, this means you have charge. The voltage you measure along the circuit will indicate the condition of the battery.
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