If this is the car heater that you are referring to, check the heater hoses are hot to touch, if both are not, check the heater control valve, the controller and the heater core for blockage, start here.
mark (mhpautos)
Nov 27, 2008 at 3:21 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.