1999 Mercury Sable 3.0 My heater is only blowing cold air. I changed the thermostat and flushed the heater core. When my engine is hot the in hose is hot and the out hose is cold coming out of the heater core. I cant check the heater control valve because I dont no where it is.
I hope you can help
Check to see if you have something in the back part of your glove box. I thought that was a strorage area for my car manual and paperwork. It was blocking the flow of air. My mechanic cleaned all my debri out and the heater worked fine.