97 Mercury Marquis 91,000 mi 4.6 eng
With heat off and a\c on blows hot air. Air comes out of proper vents ie. Uppervent when ac is on and floor or defrost when heat is on. But only blows hot very hot heater air out of all vent settings. Compressor is working and ac lines are getting as cold as they should. I suspect the problem is in either the dash vacumn or elect. Switches and or relays. The main large vacumn valve on the far right under the glove box opens and closes but for some reason the heat is not shut off. How is the best way to test the system and eleminate the sources. Where can I find out what controls what so I can run down the defective part? If it turns out to be one of those parts that require taking the dash appart could I just add a manual valve on the heater hose to shut off the water? Thanks Sarge :
have the same problem?
Monday, April 23rd, 2007 AT 10:28 AM