Having some electrical issues on my '04 EG Standard. Is the voltmeter on the dash reporting the output of the voltage regulator, or is that the output of the battery? Has anyone had a voltage regulator that has intermittent issues, or do they just die? Some back ground info. A week ago, I couldn't start the bike when leaving work. Got a jump start and was able to go about 5 miles. The voltmeter was down to 0v, started getting warning lights, and the odometer went blank. Within a few minutes, the warning lights went out and the bike started to sputter. Coasted into a parking lot and waited for the wife to pick me up. Got a new battery installed the following day and the voltmeter was reading 12v. Figured that I needed to get some road time in and the voltmeter would start to increase. Stayed at a constant 12v. Started to look for some troubleshooting tips, found the "disconnect the regulator, measure the voltage to ground, etc" procedures. Go out to the garage and start the bike. Whoa! the voltmeter reads 14.5v (approx). Figure I'll ride to work the next day and keep an eye on the voltmeter. Holds steady at 14.5v all the way to work. Bike starts fine at the end of the day, still at 14.5v. Run into rain on the way home and stop to suit up. Bike was running about 10 minutes while I was getting the suit on. Get back on the road and the voltmeter is at 12v. Ride for several miles and it goes back up to 14.5v. Run into a traffic jam a while later, sitting for about 10 minutes again. Back down to 12v and back up to 14.5v after several miles.

 

Sounds like you've already done this, but here ya go just in case....

Step 1. First things first, load test the battery. Even if it measures over 12.5 vdc it can still be bad under a load. Battery is typically rated at 19 amp hours and 270 Cold Cranking Amps (CCA).

Start the engine and measure DC Volts across the battery terminals, the regulator should be putting out 14.3 - 14.7 vdc at 3600 rpm and 75 degrees F.


Step 2. To check the regulator unplug it from the stator. Take a test light and clip it to the negative terminal of the battery and then touch first one pin and then the other on the plug that goes to the regulator. If you get even the slightest amount of light from the test light the regulator is toast.

To do this with a meter which is more accurate: black lead to battery ground, red lead to each pin on the plug, start with the voltage scale higher than 12vdc and move voltage scale down in steps for each pin. Any voltage is a bad regulator.
You may get battery voltage on all three pins on the newer 3 phase regulators.
The no voltage is for older type regulators with diode indicating the diode is bad and the regulator needs replacing.


Step 3. On the other part of the disconnected regulator plug. Set the multimeter for Ohms x1 scale and measure for resistance across the pins of the stator. You should read something around 0.1 to 0.2 ohms for the TC88 32 amp system.


Step 4. Then check for continuity between each pin on the plug and frame/engine ground. The meter needle should not move (infinite resistance)(digitals will show infinite resistance) if the meter needle does move (indicating continuity)(digitals will show some resistance), recheck very carefully. If the meter still shows continuity to ground the stator is shorted (bad).


Step 5. Set the meter to read A/C volts higher than 30 volts (the scale setting for voltage should always be higher than the highest voltage you expect or you may fry the meter). Start the bike, and measure from one pin to the other on the plug (DO NOT cross the multimeter probes! - touch them to each other). You should read roughly 16-20 vac per 1,000 rpm.


Step 6. If the battery was good under load test, if the stator is NOT shorted to ground, and the stator is putting out A/C voltage, then the regulator is bad (most likely even if if passed step 2).


Generally the following is true:
Check your owners/service manual for the system amp output for your bike.
22 amp system produces about 19-26 vac per 1,000 rpm, stator resistance is about 0.2 to 0.4 ohms.
32 amp system produces about 16-20 vac per 1,000 rpm, stator resistance is about 0.1 to 0.2 ohms.
45 amp system produces about 19-26 vac per 1,000 rpm, stator resistance is about 0.1 to 0.2 ohms.

It is possible to have an intermittent regulator connection.

 

I am having a similar problem with my 06 Ultra Classic. When I first start the bike, everything appears normal. After I ride a few minutes, my volt meter will read 14+ volts and then start to drop near 12, then drop below 12 to about 9 and the battery light and check engine light come on. A few minutes later the volts will start climbing and at about 13 volts the battery light will go out the a few seconds later the check engine light goes out and the volt meter will read 14+ again. A few minutes later this starts all over again and will keep repeating itself. Problem is getting this to act up in the garage where I can check things out. Might have to put my meter and tools in the trunk and pull over along the road and check it out.

 

Sounds like you may have had a bad connection at the regulator, that may have led to the first battery's demise. After checking the regulator you may now have a good connection. It's fairly normal for the battery to run at 12 volts after prolonged low RPM running, the voltmeter reads actual battery voltage.