2001 Dodge Caravan heater blows cold air when stopped

Have you checked the coolant level? What you describe is exactly what happens if the coolant level is low. When stopped at idle, hot coolant is not circulating through the heater core, so no heat. As the engine increases in rpm's when you pull away from the light, the water pump is spinning quicker, and some coolant is making it to the heater core. So check the level, and if it is low, keep an eye on it to see if it drops again. That of course indicates a leak somewhere. Get it fixed, as overheating the engine leads to costly repairs and worse case a new engine. Let me know how you make out with this.

Air will not blow out dash vents, works every where else. 2000 dodge caravan. heat works ac ice cold

I've checked hoses that go from the motor inside of car. Both of them just slightly worm not hot at all.