Low Voltage
Thread Starter
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Cruiser
Joined: Jul 2023
Posts: 130
Likes: 42
From: South Carolina
Low Voltage
Good morning, everyone,
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced.
What's your opinion? How would you test it?
Thanks,
Barron
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced.
What's your opinion? How would you test it?
Thanks,
Barron
Seasoned HDF Member
Joined: Aug 2006
Posts: 24,428
Likes: 30,651
From: Pennsylvania
1. How old is your battery? Always start with a good battery, if in doubt, get it load tested.
2. Have not heard about regulator 1 time use connectors.
3. Test Battery, regulator, stator in that order for electrical charging.
4. Go to the below links for testing.
https://www.hdforums.com/forum/elect...sting-1-a.html
https://www.hdforums.com/forum/elect...sting-2-a.html
NOTE:
The above information, while credible, is worth what you paid for it and should not be considered gospel.
Do due diligence, research and have a H-D Field Service Manual before working on your bike.
You will probably have many opinions and suggestions presented; make sure you research the person providing the helpful information as there are some who provide good information that is useful and some who speak out of other orifices with gibberish. You will figure out this quickly.
Good write-up from a HDF Member:@Vernal Did a good write-up on testing electrical systems here: https://www.hdforums.com/forum/touri...l#post22035780
Harley Davidson Charging System description and testing
Description:
The charging system consists of 3 major parts:
1- An Alternator that generates single phase or three phase alternating current, (AC).
The Alternator has 2 parts:
Rotor:
Attached to the primary side of the crankshaft. The Rotor has a series of permanent magnets and rotates around the Stator at engine speed.
Stator:
Attached to the crank case and has a series of wound wire coils. The Rotor fits over the stationary stator. As the Rotor spins around the Stator the rotating magnetic fields induce Alternating Current in the stationary coils. The Stator’s coils are arraigned so the AC output is either single or three phase.
2- Voltage Regulator, (VR), rectifies the Alternating Current, (AC), from the Stator to Direct Current,(DC), and limits the voltage output to a value close to 14.5 V DC.
3- Battery, a 12V rechargeable storage device used to supply power to the bikes electrical circuits.
As shown in the schematic the charging system includes insulated conductors and connectors carrying current from the stator to the VR through the main fuse to the starter and on to the battery positive. The VR negative lead and the battery negative lead are both connected to Chassis ground.
This system can be checked with a few easy tests using a digital or analog Volt–Ohm Meter:
Testing:
Connectors and cables should be checked and cleaned first. Loose and corroded connectors, terminals and grounds can cause high resistance, impeding current flow. Check cables for broken or rubbed insulation and check continuity to make sure the conductor is not broken inside the insulation.
Coating connectors with dielectric grease will keep moisture out and reduce corrosion.
Use the schematics in the HD Electrical Diagnostic or Service manual to determine the location of additional connectors.
Battery testing:
First check and clean battery terminals, Battery cables and ground connections. To check cables, disconnect one end and Ohm out, wiggle while testing. Cables can and will corrode and the evidence can be concealed under the insulation.
If you are unsure of the battery’s condition charge it fully and take it to an auto parts store and have it load tested.
Voltmeter test:
Connect voltmeter positive to positive terminal on battery and voltmeter negative to battery negative terminal.
12.7 v = 100% charge
12.6 v = 75%
12.3 v = 50%
12.0 v = 25%
11.8 v = 0%
Watch the battery voltage when you start the bike, if a fully charged battery falls below 9.6 volts it’s time to replace it.
If a well charged battery runs down if the bike sits for a short time perform a current draw test. Set your meter to read 10 amps current. Pull your main fuse and insert the meter leads. Here’s a list of components and what current they will draw in milli amps, 1/1000 of an amp) from the 2015 manual:
LHCM 0.5
RHCM 0.5
Speedometer/ IM 0.5
Regulator 1.0
ABS 1.0
BCM 1.0
ECM 1.0
Security Siren 20.0
Radio 0.5
Amplifier 0.5
CB Module 0.5
If the Battery passes all tests check the charging system.
Charging System Testing:
Volt meter set to DCV 20V scale or higher.
With the bike in neutral and voltmeter attached to the battery, start the engine and rev to 3,000 rpm. If the voltage measures 13V – 14.7V the charging system is operating properly. If less than 13V test the Stator first. If Greater than 15.5V test the Voltage Regulator.
Stator testing
Turn the bike off and disconnect the Stator from the Voltage Regulator.
Testing a 3 phase Stator, (A single phase stator is tested in the same manner but the plug will only have 2 sockets).
The end of the connector from the stator has 3 sockets. Set your meter to ohms and connect one lead to the battery negative. With the other lead make contact with the conductors inside each socket. You are checking for a grounded coil winding, each socket should show an open circuit to ground, no continuity.
Now take both meter leads and check resistance between each of the three sockets, 1-2, 2-3 and 1-3. The resistance should be 0.1 – 0.3 ohm.
Next check the Stator’s AC output. Set the meter to ACV 100V scale. With the Stator unplugged from the VR and the bike in neutral, start the bike. Run the bike at 2,000 rpm and check the Stator output between sockets 1-2, 2-3 and 1-3. The voltage should read approximately 32-46 Volts AC, for the 50 amp Stator. Stators with other Amp ratings will be similar.
If the Stator continuity tests to ground and Phase to Phase are good but the output is not the Rotor may be bad.
One other indication that the stator may be bad is if your primary oil smells like a burnt circuit board.
Voltage Regulator Testing
Voltage readings of 15.5V and higher:
Test wire from VR negative to battery negative, if less than 0.5 ohm replace Voltage Regulator. If resistance is more than 0.5 ohm check ground connection for corrosion and wire for damage.
If the output is less than 13V from the Voltage Regulator to the battery and the Stator output is good, disconnect the output cable from the VR to the Battery. Check continuity between the Voltage Regulator Positive wire and the battery Positive and the negative wire and battery negative. Repair or replace cable if needed. If the cables are good and the Stator tested well replace the Voltage Regulator.
2. Have not heard about regulator 1 time use connectors.
3. Test Battery, regulator, stator in that order for electrical charging.
4. Go to the below links for testing.
https://www.hdforums.com/forum/elect...sting-1-a.html
https://www.hdforums.com/forum/elect...sting-2-a.html
NOTE:
The above information, while credible, is worth what you paid for it and should not be considered gospel.
Do due diligence, research and have a H-D Field Service Manual before working on your bike.
You will probably have many opinions and suggestions presented; make sure you research the person providing the helpful information as there are some who provide good information that is useful and some who speak out of other orifices with gibberish. You will figure out this quickly.
Good write-up from a HDF Member:@Vernal Did a good write-up on testing electrical systems here: https://www.hdforums.com/forum/touri...l#post22035780
Harley Davidson Charging System description and testing
Description:
The charging system consists of 3 major parts:
1- An Alternator that generates single phase or three phase alternating current, (AC).
The Alternator has 2 parts:
Rotor:
Attached to the primary side of the crankshaft. The Rotor has a series of permanent magnets and rotates around the Stator at engine speed.
Stator:
Attached to the crank case and has a series of wound wire coils. The Rotor fits over the stationary stator. As the Rotor spins around the Stator the rotating magnetic fields induce Alternating Current in the stationary coils. The Stator’s coils are arraigned so the AC output is either single or three phase.
2- Voltage Regulator, (VR), rectifies the Alternating Current, (AC), from the Stator to Direct Current,(DC), and limits the voltage output to a value close to 14.5 V DC.
3- Battery, a 12V rechargeable storage device used to supply power to the bikes electrical circuits.
As shown in the schematic the charging system includes insulated conductors and connectors carrying current from the stator to the VR through the main fuse to the starter and on to the battery positive. The VR negative lead and the battery negative lead are both connected to Chassis ground.
This system can be checked with a few easy tests using a digital or analog Volt–Ohm Meter:
Testing:
Connectors and cables should be checked and cleaned first. Loose and corroded connectors, terminals and grounds can cause high resistance, impeding current flow. Check cables for broken or rubbed insulation and check continuity to make sure the conductor is not broken inside the insulation.
Coating connectors with dielectric grease will keep moisture out and reduce corrosion.
Use the schematics in the HD Electrical Diagnostic or Service manual to determine the location of additional connectors.
Battery testing:
First check and clean battery terminals, Battery cables and ground connections. To check cables, disconnect one end and Ohm out, wiggle while testing. Cables can and will corrode and the evidence can be concealed under the insulation.
If you are unsure of the battery’s condition charge it fully and take it to an auto parts store and have it load tested.
Voltmeter test:
Connect voltmeter positive to positive terminal on battery and voltmeter negative to battery negative terminal.
12.7 v = 100% charge
12.6 v = 75%
12.3 v = 50%
12.0 v = 25%
11.8 v = 0%
Watch the battery voltage when you start the bike, if a fully charged battery falls below 9.6 volts it’s time to replace it.
If a well charged battery runs down if the bike sits for a short time perform a current draw test. Set your meter to read 10 amps current. Pull your main fuse and insert the meter leads. Here’s a list of components and what current they will draw in milli amps, 1/1000 of an amp) from the 2015 manual:
LHCM 0.5
RHCM 0.5
Speedometer/ IM 0.5
Regulator 1.0
ABS 1.0
BCM 1.0
ECM 1.0
Security Siren 20.0
Radio 0.5
Amplifier 0.5
CB Module 0.5
If the Battery passes all tests check the charging system.
Charging System Testing:
Volt meter set to DCV 20V scale or higher.
With the bike in neutral and voltmeter attached to the battery, start the engine and rev to 3,000 rpm. If the voltage measures 13V – 14.7V the charging system is operating properly. If less than 13V test the Stator first. If Greater than 15.5V test the Voltage Regulator.
Stator testing
Turn the bike off and disconnect the Stator from the Voltage Regulator.
Testing a 3 phase Stator, (A single phase stator is tested in the same manner but the plug will only have 2 sockets).
The end of the connector from the stator has 3 sockets. Set your meter to ohms and connect one lead to the battery negative. With the other lead make contact with the conductors inside each socket. You are checking for a grounded coil winding, each socket should show an open circuit to ground, no continuity.
Now take both meter leads and check resistance between each of the three sockets, 1-2, 2-3 and 1-3. The resistance should be 0.1 – 0.3 ohm.
Next check the Stator’s AC output. Set the meter to ACV 100V scale. With the Stator unplugged from the VR and the bike in neutral, start the bike. Run the bike at 2,000 rpm and check the Stator output between sockets 1-2, 2-3 and 1-3. The voltage should read approximately 32-46 Volts AC, for the 50 amp Stator. Stators with other Amp ratings will be similar.
If the Stator continuity tests to ground and Phase to Phase are good but the output is not the Rotor may be bad.
One other indication that the stator may be bad is if your primary oil smells like a burnt circuit board.
Voltage Regulator Testing
Voltage readings of 15.5V and higher:
Test wire from VR negative to battery negative, if less than 0.5 ohm replace Voltage Regulator. If resistance is more than 0.5 ohm check ground connection for corrosion and wire for damage.
If the output is less than 13V from the Voltage Regulator to the battery and the Stator output is good, disconnect the output cable from the VR to the Battery. Check continuity between the Voltage Regulator Positive wire and the battery Positive and the negative wire and battery negative. Repair or replace cable if needed. If the cables are good and the Stator tested well replace the Voltage Regulator.
Last edited by CoolBreeze3646; Jul 26, 2025 at 09:30 AM.
Road Master
Joined: Jun 2013
Posts: 1,239
Likes: 1,171
From: St. Catharines, Ontario
check those voltages using a decent DMM right at the battery terminals. I only use the fairing mounted voltmeter as a rough guide. There are a few connections on the path to the meter that can skew the indication. I also believe you can calibrate it if way off.
Is it throwing low voltage codes?
Is it throwing low voltage codes?
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,830
Likes: 7,968
From: poway
Good morning, everyone,
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced.
What's your opinion? How would you test it?
Thanks,
Barron
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced.
What's your opinion? How would you test it?
Thanks,
Barron
What kind of voltage are you getting at idle.. You may want to use a voltmeter across the battery terminals. Make sure your battery terminals are tight at both ends..
Pull the clutch cover and smell the inside. Does it have a burnt smell?
Seasoned HDF Member
Joined: Sep 2008
Posts: 14,077
Likes: 11,099
From: San Diego, CA
Good morning, everyone,
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced. What's your opinion? How would you test it?
Thanks,
Barron
2011 Ultra does not charge when starting first time of the day. Once the engine is warm, I rev it to 3,500 and the voltmeter will always go to 14+. I tried yesterday to let it get thoroughly warmed up by riding 10 miles without exceeding 3.000 and it never charged until I revved it to 3,500 then it will charge all day, even when I stop and turn the engine off for a break and restart.
I know how to check voltage to and from a regulator, but my Harley service manual states that the regulator connectors are one time use only and once disconnected the regulator must be replaced. What's your opinion? How would you test it?
Thanks,
Barron
I have never seen, or noticed, in any of my HD Service Manuals a one time use "connector". Could you say the section and page you saw that in...? If I've missed it, I'd love to see it in full context..
I have disconnected a voltage regulator a couple times, and reconnected with no issues...
I recently replaced a 2012 bagger stator, which the HD Service Manual says has one time use mounting screws....
As for testing the voltage regulator:
Thread Starter
|
Cruiser
Joined: Jul 2023
Posts: 130
Likes: 42
From: South Carolina
Where is that in the manual? I've not ever read this. FWIW you probably don't want to check the regulator output without it connected to a battery tho.
What kind of voltage are you getting at idle.. You may want to use a voltmeter across the battery terminals. Make sure your battery terminals are tight at both ends..
Pull the clutch cover and smell the inside. Does it have a burnt smell?
What kind of voltage are you getting at idle.. You may want to use a voltmeter across the battery terminals. Make sure your battery terminals are tight at both ends..
Pull the clutch cover and smell the inside. Does it have a burnt smell?
So it means IF the terminals are damaged.
I am getting only 12 ish volts at the battery until it is revved to 3,500 rpm. Stator does not smell burnt. Battery is one month old, same issue with old battery, terminals are clean. Since I am confident that I can disconnect the stator connector from the regulator, I will check the AC voltage and reply.
Thanks again for your help.
Thread Starter
|
Cruiser
Joined: Jul 2023
Posts: 130
Likes: 42
From: South Carolina
Thanks CoolBreeze for the detailed information. You have gone above and beyond the call. I will do further testing as per your recommendation and report back in.
Thanks again!
Thanks again!
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Thread Starter
|
Cruiser
Joined: Jul 2023
Posts: 130
Likes: 42
From: South Carolina
I have never seen, or noticed, in any of my HD Service Manuals a one time use "connector". Could you say the section and page you saw that in...? If I've missed it, I'd love to see it in full context..
I have disconnected a voltage regulator a couple times, and reconnected with no issues...
I recently replaced a 2012 bagger stator, which the HD Service Manual says has one time use mounting screws....
As for testing the voltage regulator:
https://www.youtube.com/watch?v=bVThKEKr5hU&t=159s
I have disconnected a voltage regulator a couple times, and reconnected with no issues...
I recently replaced a 2012 bagger stator, which the HD Service Manual says has one time use mounting screws....
As for testing the voltage regulator:
https://www.youtube.com/watch?v=bVThKEKr5hU&t=159s
Thanks again!
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Seasoned HDF Member
Joined: Dec 2005
Posts: 19,830
Likes: 7,968
From: poway
Thanks for the reply, Max. I may have misinterpreted the information in the manual. It states. [THE RUBBER MOLDED VOLTAGE REGULATOR AND STATOR CONNECTORS ARE NOT SERVICEABLE. DAMAGE TO TERMINALS, MOLDING OR LOCKING LATCHES REQUIRES VOLTAGE REGULATOR AND OR STATOR REPLACEMENT]
So it means IF the terminals are damaged.
I am getting only 12 ish volts at the battery until it is revved to 3,500 rpm. Stator does not smell burnt. Battery is one month old, same issue with old battery, terminals are clean. Since I am confident that I can disconnect the stator connector from the regulator, I will check the AC voltage and reply.
Thanks again for your help.
So it means IF the terminals are damaged.
I am getting only 12 ish volts at the battery until it is revved to 3,500 rpm. Stator does not smell burnt. Battery is one month old, same issue with old battery, terminals are clean. Since I am confident that I can disconnect the stator connector from the regulator, I will check the AC voltage and reply.
Thanks again for your help.
Seasoned HDF Member
Joined: Feb 2007
Posts: 6,067
Likes: 1,121
From:
What is the history of ownership of this motorcycle?
Is this a new situation?
What are you using to measure voltage?
Your tool for measurement is not clear.
Hopefully a digital meter at battery terminals and not a dash meter.
The dash/fairing meter is not accurate and can have other items on the same line.
Note: In 2012 the touring models had a batch of bad regulators.
Is this a new situation?
What are you using to measure voltage?
Your tool for measurement is not clear.
Hopefully a digital meter at battery terminals and not a dash meter.
The dash/fairing meter is not accurate and can have other items on the same line.
Note: In 2012 the touring models had a batch of bad regulators.