Okay, bike is a 2008 FLHT. Bought new. Now at 127,000 + on the clock. Last December, had to replace the stator. This February, replaced the voltage regulator. Out for a ride late last month, volt meter starts reading under 13. I headed for home, with everything shut of that shuts off. Got home with it showing just over 10 volts. Did all the appropriate tests called for in the factory electrical system manual. AC output right where it should be. Static resistance right where it should be. Voltage regulator tested good. Battery tested good, both voltage, and load test. All fuses and relays good. Checked ground wires for resistance or damage. Grounds all checked out. Pretty frustrated by this point. Decided to check continuity on the VR output wire. No resistance at all. Turned out to be the connector inside the output plug had broken. Manual doesn't cover checking for that. Modified an electrical connector I had, stuffed it into the rubber plug housing, and voila! 14.5 volts at idle. So, if all the usual stuff checks out, but you get nothing to the battery, check that stupid little plug.

 

Goodonya!!

 

Great troubleshooting steps! Most guys on here have a hard time figuring out where to put their gas caps when filling up!

 

Thx for sharing the fix

 

Which exact plug is this?

 

I thought I made it clear which plug it is. There are only two connectors on the voltage regulator. AC volts IN, and DC volts OUT. The one I talked about was the DC volts out. The one with two wires. The AC in is a 3 phase, meaning 3 wires. The connector INSIDE that plug is what was broken.

 

The other one that you need to keep an eye on, is the main breaker that can internal corrode as well.


Hence on older systems, DC positive out of the regulator goes to one side of the main breaker box, then other side goes to the cable that goes to the positive starter terminal to connect to them main positive battery terminal. So even if the battery cable connection is clean, you can have corrosion on the starter to main breaker cables connection point, or at the contacts inside the main breaker than may have corroded isntead.
Note, you can pull the older main breakers apart to clean it contact points, but since you can replace it for less than $8, just not worth the effort.

Hence starter terminals are easy to check for corrosion, and if you are replacing the stator, the main breaker is less than $8, and should be replaced as well.

On newer bikes, instead of having the main breaker type box, you just have a standard plug in type fuse, so that needs to be check for corrosion at it legs/spades at the connector isntead.


And again, both systems has the charging system running through the positive terminal on the starter as the bride point, so make sure that you clean the cables and terminal there.


To add, to really help out the system, it does not hurt to add in a ground jumper wire from the trans ground point, back to the frame ground point for the regulator, for a better ground back to the battery on the charging system side. The primary case is aluminum, and it's threads for the starter bolt can oxide over time to get a less then stellar connection. With jumper in place, you have tinned connectors against tinned connectors back to the ground of the battery on say 8 gauge wire from the regulator, and not at the mercy of oxidation problems with the ground running back through the motor to get to the grounded frame on the regulator ground side.

 

Good job Musician, The 08 EDM just mentions checking the ground wire from the VR :

"Voltage Regulator Inspection The voltage regulator must have a clean, tight connection for proper operation. Check by using an ohmmeter with one lead on chassis ground, such as battery ground cable, and the other on the voltage regulator ground lead"

I would have thought they might say check one lead for 12V and the other is the grd, check it for continuity?

Dano, isn't the only thing that grounds through the starter bolt the starter itself?

 

Where do you all put your gas cap when filling up?

 

Bravo!! good read. great question that you also had the answer for. thanks for passing that along.
kroozeabout.