I was having a problem with my tail lights. Brake light would come on, on the right side, when the tailight should come on and tailight would come on when the brake light should come on (dash board bulb failure light would light up whenever the lights were on or brakes used, most annoying). I had replaced the entire left side tailights due to a little fender bender (ouch) with parts from FCP Groton. So now I had an aftermarket brake light on the left side and a volvo brake light on the right side. I called FCP Groton, they were very helpful, sent me an after market socket for the right brake light (no charge). I swapped this with the original light and voila, problem solved.