Why my 2005 Cadillac Deville DTS headlights low beams will not work?

What is your question?

Low beams only work in drive. If I turn the switch, brake lights will only come on. High beams and turn signal work. Ive checked fuses, regulators, turn switch, light switch, and headlight control sensor on dash. Has anyone seen this before?

How long has your 2005 Cadillac DeVille had this problem?

Since I bought the car 3 weeks ago