I changed out the OBC light bar this weekend on my '88 M3. I thought everything was fine, because when I started the car, it lit up. However, later that night when I turned on the headlights, the OBC light went out. When I turned the headlights off, the OBC light came back on. I did not remove any connections or install any in the OBC except the light bar. Any ideas on what may be the problems?