It very likely has something to do with a programming change for the lighting circuits. The Rams have computer monitored and regulated headlights and there was very obviously a change between the 2009-2014 models and the 2015 models. Even though the physical bulbs and housings can be the same. It is either a change to the sensitivity of the headlight circuit or its a change to the PWM signal which doesn't sync well with the normal normal HID kits. This is why we have an HID system specifically for the 2015 models which is totally different than the previous model years.