I’m new here, and just picked up a 2003 STS for a work car. When I start it, to warm it up (25 degrees out), it seems like it takes forever to blow warm air. The temp gauge rises up, to let’s say normal (half way) and it seems to keep blowing cool air until I’ve been driving for 10 minutes. What should I be looking for? I can change it from defrost to floor, to vent, but it takes awhile to blow warm after running for 15 minutes.