good morning dudes and dudettes. I'm in billings mt (home is dfw texas area). My 2004 Police Electraglide (FLHTPI) is doing a sort of odd thing. If I get over 3100 RPMs, the volt meter moves down to 12 volts and then immediately moves back up in a smooth sweep. The bike is staying charged. If I don't get over 3100 rpm, its steady at 14.9 volts. It's sort of like the voltage regulator is not liking the stator spinning too fast. I've had this bike for 5 months and it has 40K on the clock. My questions are "Is this normal"? and "Is it probably the voltage regulator?" and "If you were me would you buy a regulator and install it or wait til home?" again, the bike is staying charged, running as normal, and all lights are bright.

3100 rpms is exactly 70 mph, so no problems riding it the way it is if it isn't going to suddenly get worse.












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No it's not normal and while it may be the regulator, don't assume it is! There are a couple of threads on checking your charging system in the Tech Electrical section, so do read them. You will need a multimeter to diagnose the fault, which should identify the culprit. The problem on your bike could be a very simple thing, such as a poor electrical connection or ground, which vibration is making intermittent, so look into that before doing anything more drastic.

 

The two most likely causes are the regulator and the stator.
My thought is it's a stator related issue because it's rpm related. The regulator doesn't care what the engine rpm is, the stator does.
Of course that's just speculation without proper troubleshooting. There's a guide above on the steps to take.
A quick and dirty test might be to pull the primary derby cover and smell the primary fluid. I'm told it has a very strong and distinctive burnt odor when the stator is starting to fry. But, again, that's no substitute for a proper check of the system.

 

IMHO...if your battery is staying charged, I wouldn't swap out any parts until you can do some diagnostics. That does not sound like a normal regulator failure. Could be, loose connections, stator, volt meter.

Things to consider:
- does it do the same thing at 3,100 in neutral...or with clutch in?
- have you tried measuring the voltage with a digital volt meter...it could be a defective built in volt meter
- check the connections to the regulator, and the cables at the battery.
- use the diagnostic procedures that are stickies in the electrical section

 

If you have a voltmeter you could check the charging system. You can pick one up at most any big box store for less than $30. If your not able to do that I'd take it somewhere and have someone check it out. For some reason your charging system is "opening " at that rpm. Check the connections from stator to Reg and Reg to battery and ground, make sure all battery connections are good and clean. Here are some instructions I wrote up a while back:

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.