Hey all. I had to check my charging system today, and it never hurts to get a second opinion on this site Anyway, since there don't seem to be any instructions for a system check in my service manual, I followed these instructions from the DIY section of this site: https://www.hdforums.com/forum/elect...sting-1-a.html
I'm pretty sure I did everything correctly, but a second set of eyes never hurt.

Anyway, my after charging the battery overnight, it's holding a charge of 12.7V. With the engine idling the battery checks at about 13.8V.

Checking the voltage at the regulator plug shows 11.xV at each terminal.

Checking the resistance across each pin of the stator shows 0.7 - 0.8 Ohms

The resistance between each pin from the stator to the frame ground shows infinite resistance.

The output at idle of the stator is about 20 VAC. Revving the engine causes an increase in voltage, as it should.

So, according to the instructions, I should have a bad regulator. Since I have an 06, I was suspecting it would be the rotor bolts, so maybe this is the silver lining.

My question is, am I reading everything in the instructions correctly? I must have read through them 4 times, but sometimes you miss something and everything else gets taken out of context. Any help is appreciated.

 

I could be wrong....but, the following readings would lead me to believe your charging system is OK.

"after charging the battery overnight, it's holding a charge of 12.7V. With the engine idling the battery checks at about 13.8V".


"The output at idle of the stator is about 20 VAC. Revving the engine causes an increase in voltage, as it should"

So what are the symptoms?.

 

The major sympton is that the battery dies after a few rides. My original battery (3+ years old) died last month, so I just figured it was time for a new one. When the new battery died after just a few rides in 1 month, I checked the charging system.

According to step 2, the voltage at the regulator end of the regulator/stator connection should be 0. I'm getting 11.xV at each pin. This, along with the fact that my brand new battery took a dump after only a few short rides, leads me to believe the charging system, specifically the regulator, is at fault. Even though the voltage at the battery reads 13.8 at idle. I just want to make sure I'm reading the instructions correctly.

 

Have you taken your battery in to get checked to see if that is a problem? I had a battery go out around 6 months and it was a bad cell.

 

Sporty, as I read the instructions I believe you have reached the right conclusion. If you are measuring a voltage at the pins on the regulator that go to the stator (with the stator disconnected), that would indeed be a bad thing.

 

Thanks for the responses guys. It is indeed the regulator. I spoke with a friend of mine who happens to be an indy, and he confirmed it. There is a diode in the regulator that should prevent current reversal. It's shot, which is why I can measure voltage through the regulator. At least it's a faster/cheaper fix than the stator.

 

Don't be so quick to think you don't have a problem with the stator. I just went through a similar problem. Testing indicated the voltage regulator was bad and everything else was good. I replaced the voltage regulator and battery. The bike was fine for a little bit, but then I had problems again. The stator *was* bad. It was putting out the right numbers at idle and at increased RPM's. No ground. ...but it did have an open.

Try the voltage regulator. Might be the problem. Check the voltage coming in to the battery at idle a few times after you replace the regulator. I was getting 13.7-13.8 @ idle right after I replaced the voltage regulator, but, within a couple of days, I was back to getting the same reading at idle or off.

Your service manual probably references an electrical repair manual for your bike. Mine cost $60 from the dealer, but it's well worth it.