Got a problem with a F-350. High/Low beams not working. Daytime running and park lights are working. When I turn on the headlights, the daytime running lights shut off and the park lights stay on. Turn off the headlights and the daytime turns back on. High beams don't work however, when I flas the high beams they work. I checked the headlight bulbs and they're good. I'm just wondering if it's the light switch or the Daytime running lights module.