so i have a 07 nightster put a new battery in last week now i get the check engine and batt dummy lights they come and go. there on for a few min then off for a few min and so on. checked and cleand all battery conections they are all tight and clean. checked codes and got po562 and po563 low voltage and high voltage does this sound like the voltage reg or stator i have a 400+ mile trip this weekend and dont want to get stuck any ideas

 

Wow - where to start?
At rest a fully charged battery should measure 12.9 volts! A reading of 12.7 volts means that the battery is 25% discharged! When starting the bike, the voltage may drop off to the lower 12s but should not go any lower. At a high idle the reading at the battery should be 14.2 to 14.5 volts.

That being said, you need to start at the beginning. Make sure ALL the connections (at the battery, starter and grounds) are clean and tight. Just because the battery is new DOES NOT meen it is good. Make sure it is fully charged! A tender IS NOT a charger. Over voltage is indicative of a bad regulator, undervoltage can be wiring, battery or charging system.

 

Start at the beginning is right. The beginning is the stator. If you have a volt meter, it's easy to check the stator. Unplug the voltage regulator and there are two holes in the plug coming out of the stator. With the engine running around 2,000 rpm the output from the stator should be very high (around 140 amps) and this will be AC current not DC.

There is no way to check the voltage regulator. Check the battery as suggested above. If the stator is good, and the battery checks out good, then you have a ground issue somewhere. If the stator checks good, and the battery doesn't test out, then it's the voltage regulator.

If the idiot lights come on and then go out, I would suspect a bad connection somewhere. In addition to checking connections, check for corrosion on the fuses, particularity the Maxi fuse.