Tech Ref for charging voltage?

[Sporadic]

Hey all. I'm pretty sure I have a VR issue on my 2008 Mastiff. Bought the bike new last March (left over model). Battery was kept on a tender all winter. Stator checks out fine per troubleshooting flow chart I found on here (20v @ 1000 RPM), but I'm seeing no increase in voltage at my battery or circuit breaker while the bike is running. From everything I've read, I should be seeing between 13.8 and 14.8 provided my battery is charged and in good condition (which it is). I have no issues starting the bike and am good for ~80mi off a freshly charged battery. Dealer says they can't reproduce the issue and they won't replace the VR under warranty if they can't reproduce it. Is there some service manual bullet or specification stated from BDM somewhere that I could reference to the dealer / mechanic. I'm planning on riding down to Daytona next Thursday and currently do not have much confidence in my bike. Thanks.
-shelby

 

[bigdogtech01]

Hey all. I'm pretty sure I have a VR issue on my 2008 Mastiff. Bought the bike new last March (left over model). Battery was kept on a tender all winter. Stator checks out fine per troubleshooting flow chart I found on here (20v @ 1000 RPM), but I'm seeing no increase in voltage at my battery or circuit breaker while the bike is running. From everything I've read, I should be seeing between 13.8 and 14.8 provided my battery is charged and in good condition (which it is). I have no issues starting the bike and am good for ~80mi off a freshly charged battery. Dealer says they can't reproduce the issue and they won't replace the VR under warranty if they can't reproduce it. Is there some service manual bullet or specification stated from BDM somewhere that I could reference to the dealer / mechanic. I'm planning on riding down to Daytona next Thursday and currently do not have much confidence in my bike. Thanks.
-shelby

Yes, Holding your meter leads to your battery posts you should have at least 13.5 and no more than 14.6 @ 3000 RPM. You said you did check output on your stator, 1k rpm, 2krpm and 3k rpm? Also make sure you have no opens or grounds using your ohms setting, check continuity threw the output wire of your stator. Check both wires to make sure there is no open or continuity to ground.
If the stator passes all tests then, yes most likely it is the Voltage Regulator. You said you are getting the same reading on both sides of your circuit breaker?

 

[Sporadic]

Yes, Holding your meter leads to your battery posts you should have at least 13.5 and no more than 14.6 @ 3000 RPM. You said you did check output on your stator, 1k rpm, 2krpm and 3k rpm? Also make sure you have no opens or grounds using your ohms setting, check continuity threw the output wire of your stator. Check both wires to make sure there is no open or continuity to ground.
If the stator passes all tests then, yes most likely it is the Voltage Regulator. You said you are getting the same reading on both sides of your circuit breaker?

I only tested the stator at ~1k (idle) and read ~20v as I didn't have a way to keep the leads in while throttling. My dealer said they checked the output though and that the stator checks out OK. I did however go to 3k while testing voltage at the battery and breaker (including VR side of breaker). I read 0.6ohms from the VR heatsink cover to the negative battery post. Where's a good place at the VR to check continuity on the output wire since there isn't a plug? Can I take the VR apart and get to it? I haven't traced the wires from the VR to the circuit breaker yet, but I assume there are no plugs in between I need to check? I'm planning to pick the bike up tomorrow and taking my own meter to test it in the parking lot before I leave. If it's not in spec, I want to tell them why and hopefully have some documentation to back it up. What scares me mostly is that it's some intermittent problem that's going to leave me stranded halfway to Daytona. Guess I should put a meter on it and just beat on stuff until something happens... Thanks for the help Andrew!

 

[MARV]

make sure the washers on the bolts holding the VR in place are star washers.

that is the ground for the VR and the star washer will give a better ground to the frame.

wire from VR to CB is 1 piece

 

[bigdogtech01]

I only tested the stator at ~1k (idle) and read ~20v as I didn't have a way to keep the leads in while throttling. My dealer said they checked the output though and that the stator checks out OK. I did however go to 3k while testing voltage at the battery and breaker (including VR side of breaker). I read 0.6ohms from the VR heatsink cover to the negative battery post. Where's a good place at the VR to check continuity on the output wire since there isn't a plug? Can I take the VR apart and get to it? I haven't traced the wires from the VR to the circuit breaker yet, but I assume there are no plugs in between I need to check? I'm planning to pick the bike up tomorrow and taking my own meter to test it in the parking lot before I leave. If it's not in spec, I want to tell them why and hopefully have some documentation to back it up. What scares me mostly is that it's some intermittent problem that's going to leave me stranded halfway to Daytona. Guess I should put a meter on it and just beat on stuff until something happens... Thanks for the help Andrew!

Like MARV said, wire from VR is one piece all the way to the CB. I would get a friend or someone to help you with testing the Stator output again. Just because it is ok at idle does not mean it is necessarily good above that. It should be close to 10-15 VAC with every 1k increase to 3k. So @ 2k it should be around 30-35 VAC and 3k should be 40-45 VAC.
If everything tests good with the Stator, you know it is the VR. If the bike is under warranty, do not poke into any wires. If the dealer is already giving you a hard time, you don't want to give them a reason to deny your warranty.
Why is the dealer giving you such a hard time anyhow? Seems like most of them are very friendly, unless they are an H-D dealer

 

[outdoorsman26]

tell them ta take it foe a 80mi ride!! hopefully they think about what they said to you while they are walkin back to da shop!!!

 

[RADAMS445]

tell them ta take it foe a 80mi ride!! hopefully they think about what they said to you while they are walkin back to da shop!!!

:roll::roll::roll::roll:

 

[bigdogtech01]

tell them ta take it foe a 80mi ride!! hopefully they think about what they said to you while they are walkin back to da shop!!!

Sometimes this is the only option, to ride the bike until the problem starts. In the past I have had customers state the problem is only there after 30-40 miles. So the only way to confirm this is to take the bike out on a long ride. You do whatever it takes to find and fix the problem. It sounds like this is not the case for this bike. It doesn't sound like an intermittent problem, rather just for whatever reason, the dealer just does not want to fix it:loony:

 

[Sporadic]

Problem resolved. I went to pick the bike up today and the service manager informed me they finally reproduced the problem last night. Seems it was intermittent as they've been testing it for 3 days. They put roughly 30 miles on it according to the tach and finally had the charging system fail. Dealer confirmed it was the VR and had a new one already installed! Heading to Daytona this week with some confidence back in my dog Cheers to the service manager, David at American Biker in Charleston for taking care of me and Mark in sales. Both are great people to work with. And major thanks to the forums for the wealth of information and expertise of its members!