no hot AIR BLOWING FROM HEATER (CAR)?

the heater in my car will not blow hot air all the time but it will blow hot air for awhile and then quit and then start again. It seems to help when i put new anti frezze in the car. when it quit s working there is still plenty of fluid in the car. please help. thank you for your time.
Roderick Schild, January 2005


done
What type of car........blower quits or heat quits with blower still working..???

bg, October 2005