Hi folks,

I have the following situation on my 2013 FLHX.

After riding the bike, I always put it on a HD battery tender and I notice the indicator light going from yellow to green within a minute or two, and the bike also starts without hesitation while out riding, which makes me believe that my battery is being charged properly while riding.


However until a few days ago when starting the bike sometimes the voltage indicator would stay at 12V and when I started riding the no-charging warning light came on after a minute or so. If I turned the bike off and waited a few seconds and then started again the voltage meter would often jump up to around 15V and all was good, sometimes I had to turn the bike off and on a couple of times until the voltage meter showed 15V, but once it did it would stay at 15V for the entire ride.

Since this weekend however the situation has changed in that now, the voltage meter will sometimes stay at 12V when I start the bike, but when I start riding it will fix itself and get up to 15V. Unfortunately what happens next is that in the middle of the ride, the voltage will drop to 12V and remain there for several minutes however the no-charging warning light does not come on and the voltage autocorrects to 15V again.

I also believe to have noticed there to be a correlation between RPMs and the voltage drop off and recovery, if I keep the bike at 3000rpm or above the voltage drop off does not occur as frequent as when I have the bike below 3000rpm but this could be completely circumstantial and have nothing to do with anything.

I do not have any heavy power consuming items on the bike, standard radio with a HOGTunes amp and only fairing speakers, and the HD Daymaker headlight, I also have the BadDad Summit fender with the large LED panel and stretched saddlebags with LED lights as well.

I've not yet done any of the workshop tests on the stator as I don't have a multimeter yet (ordering one today).

I've double checked all the battery wiring connections and they are good, checked the starter motor connections, voltage regulator connections they all check out a-ok.

Now before I start replacing parts at random, which one is the most likely? Stator? Voltage Regulator? Battery? Anything else?

 

You can go to any Lowe's, Home-depot or Radio Shack and get a voltmeter for $25.


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 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.
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It's most likely to be a Voltage regulator problem.