I just replaced a heater core in my wifes 98 grand am, and now I have no heat it just blowes out cold air.....I spent half a day working on this and I am about to send this car to the junk yard...Can anyone help me out. Since I changed the heater core the temp changer is very hard to move now and I never even messed with it. Hoping and Praying someone here can help me out...Thanks Jer