The heat in the car is no longer working, but it will kick on for a few seconds here and there. Also, it has nothing to do with how fast/slow the blower is set. In the summer I noticed my car wasn't cooling off as fast or as much either. I don't drive too frequently but the car has a little over 100,000 miles.
Car won't heat up on 2001 Ford Focus
by KashaKat in Philadelphia, PA on January 07, 2011
ANSWER by sheaffer on January 07, 2011
check you coolant, might be low.
ANSWER by DaveJHM on January 07, 2011
I'm assuming you mean the blower kicks on and off sometimes? If so, check the blower motor resistor - it has probably failed and/or melted its wiring connector.