I have an 03 Ram 1500 4.7. Last year I had little to no heat blowing. This past summer I replaced the thermostat, flushed the cooling system including the heater core and a new radiator cap. When I turn on my heat on low fan speed I feel a very small amount of heat. If I turn the fan on high it is only cold air. What should I do next?

 

Im having the same problem but mine blows hot air on the passenger side and cold air on the drivers side still trying to figure out the problem