I have a 2012 ultra classic with just over 15k on it. Had the dealership put a new rear tire and 15k service a couple weeks ago. I put an LED headlight on it last weekend and the passing/spots on tonight. Went for a ride and within 5 miles the check engine light and the battery light came on. I had the regulator changed out in april or may. Before I replaced the spots I have been noticing a burning smell just a little but haven't been on a long ride since the service......any ideas what could be wrong???

 

I would suggest taking it in to the dealer since it is still under warranty. But if you would rather try to diagnose it yourself, here are a few things to get you started, hope this helps.

Check battery and ground connections first, if they are ok, move to the next step, if you have a digital multi-meter check and see what your voltage at the battery is with the bike running, should be at least 14.0 - 14.5 volts, if it's in the 12 volt range or below, you are running off of the battery only, rev the bike to 2000 rpm and see if voltage increases, if it does either your stator or voltage regulator is going out, if it doesn't increase and stays in the 12 volt range, the stator or regulator is probably already gone bad.

 

No where near enough info to give any decent feedback, but like pswomack says, better off getting it sorted under warranty, especially as you say the regulator has been replaced already