After car is warmed up, I turned the temperature switched to Hot. The blower continues to blow cold air.What could be the problem?
Heater on 1993 Honda Accord
Monkeyrench is right check the coolant level first, but a low coolant level on this car often causes a surging idle speed. One simple thing, the black plastic knob that is rotated to operate the heat from hot to cold frequently fail, the knob may appear to turn but does grip the spindle behind it to turn the heater from cold to hot. Pop the knob off, it will pop straight off with gentle pressure from two small screw drives, look at the back of the knob, see if it is cracked in the center, a new one is about $5 and the dealer always has them in stock. Once the car is warmed up and you are driving on the road does the temperature gauge get up to the middle of the gauge, if it remains only 20% or so up the gauge the cooling system Thermostat may be stuck open.
First, make sure the coolant level is OK. If it is, the heater core may be plugged, or the heater valve and/or cable may not be working properly.