2003 Dodge Caravan Airbag light

Nope. The Air Bag Computer monitors a number of different circuits, and when it detects a problem, it turns the system off so it won't deploy in a crash, it sets a diagnostic fault code to indicate which circuit needs further diagnosis, and it turns the warning light on to tell you. The place to start is by having the code read and recorded.

The place to start with the lack of heat is to observe the temperature gauge on the dash, and to feel the radiator and heater hoses after the engine has warmed up. They should be too hot to hold onto for very long.