thanks for the tip. but the bulbs are the original stock ones so i can't see why they would be the culprit, i can understand if they were aftermarket high wattage bulbs how that could be the case. the warranty is the original manufacturer's 3yr-36,000mile warranty. i'm at 33,000+ miles now, so if i can find the culprit before the warranty expires that would be great. if not, i guess i either accept the dimming or out i'm out of pocket on the repair.