Went to work this morning had no heat all day. Heater core was replaced about six months ago and bought and installed a new thermostat today. Still no heat. Any suggestions?
Maybe a bad blend door actuator?
Low coolant level?
What model and year Pontiac? Describe the problem a little more. Do you have air flow? Is there a temperature gauge? If so, what does it show after the car heats up?
Checked coolant it is not low. Car warms up and sits the correct temperature it’s always ran at just for some reason won’t blow hot air, flow is fine. It’s a 2004 Grand Prix GT. Radiator was replaced 2 weeks ago. I thought maybe water pump not getting coolant to the heater core but there’s no leaks indicating it’s bad.
Make sure your blower motor is blowing, could be as simple as a blower variable resistor needed.