Forum members,

I ride an 07 FLHT with 42K miles. Recently I started experiencing a problem I have never had before: about once every 7 or 8 starts, my bike's voltmeter will show 10 volts and stay there after the bike is running. Within a few seconds later, the battery warning indicator will illuminate on the speedo along with the check engine light. Sometimes the voltmeter will slowly climb up to 14 volts and then the battery indicator and check engine light will go out. Other times, the only way to get the warning lights to go out is to pull over to the side of the road, shut off the bike, turn off the ignition, wait a few seconds, then go through the start sequence again. Sometimes I have to do this more than once before the issue goes away.

My battery is about 8 months old and is a HD battery. When I check to see if I have any trouble codes, I get nothing. My theory is that my alternator may be going out, but with all the electronics on the bike to include the myriad of relays, I really have no idea what's happening. My bike is not under warranty of course, so I really don't want to take it to a dealer to have the problem diagnosed and go broke in the process.

This problem is really stumping me because it's intermittent and I need to figure out what the hell is going on before I become stranded in the middle of nowhere...a place my wife and I often find ourselves!

Help!!!

Thanks in advance to any of you who may know what's happening here.

Mike

 

Have you checked the cables on the battery? Make sure they are tight.

 

Check your voltage regulator. I had similar problem. Bike ran fine, but after ~ 2 miles. Voltage dropped to 10V and check engine lite came on. When it first happened, I rev it up and it jumped back to 14V. Eventually, voltage never got above 10V.

I thought was the stator. My indy checked it and found out it was the regulator was going out. Replaced and everything is fine now.

I also replaced the battery after that, since it was OEM since 2008 with almost 60k miles. Dropped in a Big Crank, did not leave old battery on the tender, almost a month now, OEM battery still holding @12.78V, probably still last me another year.

Sorry about the long post. Hope this help.

 

How to check the charging system.

the very first thing you do is check your battery voltage. should be at least 12.7v (DC) or more. if not, charge your battery. after battery is charged, verify the voltage by hitting the start switch to turn engine over, dont start it, just take the excess charge off the battery. should be 12.7v or better afterwards. if not, take it to auto zone and have it tested for free.

using a digital multimeter, set on volts ac (very important volts AC), fire the bike up, remove the leads from the stator (front of engine - bottom right side - front of primary) there will be two holes to put your DMM leads (doesnt matter which way) the output should be 16v (AC) - 20v (AC) for each 1000 rpms. ifyou rev the engine to 2000 rpms, it should read 32v - 40v. 3000 rpms - 48v - 60v etc.
if not, bad stator. do yourself a favor and replace the stator and rotor

to check voltage regulator, (after stator output has been verified) reconnect stator output leads, very important --- CHANGE setting on DMM to volts DC --- , place positive lead from dmm on positive battery terminal, now negative on negative terminal, with the bike running voltage should read between 13v (dc) - 15v (dc).if not, rev the engine a little to see if it goes up.
if <13 or >15, probably a bad voltage regulator.

 

i had this kind of trouble myself! the old harley mechanic said if your stator goes, you will smell it! tuffist problems are always the ones that come and go! i replaced the regulator and the problem went away! cheers from montana