2003 1500 heat problem
#11
I had the same problem, it is your heater core or blend doors. Go to heatertreater.net, they show you how to check the blend doors. If thats not it, you might have a plugged heater core. Try flushing it with a water hose and see if anything comes out of it. Be sure and bleed the system after you put everything back together to get the air out.