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Old 08-22-2007, 11:09 AM
tecqboy tecqboy is offline
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Join Date: Mar 2003
Location: Milwaukee Wisconsin
Posts: 1,150
I should have said passanger side of a US car. The valve is normally "open". That means with no power, it passes water. It requires a 12V "signal" from the controller to stop the hot water. The valve opens with the ignition off, so hot water gets to the heater core when you turn off the key. If you come back and restart after a few minutes, you get un-wanted heat until the AC cools the core. If you are in EC mode, especailly on a warm day, it takes a long time for ambient air to cool the core down. I wouldn't assume a bad MONO valve just because you are getting heat when you don't want it. There has been much written on this forum about the HVAC system on this car. You can do a "search". You'll find info on how to clear all the error codes from the controller and check all the temperature sensor values. And finally, realize that it was designed primarily to be run in the AUTO mode at all times. EC is OK for heat in the winter, but poor for non AC fresh cool air in summer. The blend doors run on vacuum and the vacuum motors do fail too.
Resistance is Futile.
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