My girlfriend has a 2004 Pontiac Sunfire. When she puts her parking lights on and into drive, only the left one turns on and begins to flash. The flashing stops when taken out of drive, or the e-brake is pulled. Also, when the lo-beams are turned on, only the left comes on. When the hi-beams and turned, the left lo-beam turns off, and the right hi-beam turns on. The ground is good, no burned out fuses, changed the relay in the fuse box, and also the headlight/turn signal switch. The bulbs look good, no broken filaments. Any suggestions?