Thread: Monovalve
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Old 10-23-2006, 12:28 PM
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mplafleur mplafleur is offline
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Location: Lathrup Village, Michigan
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Quote:
Originally Posted by djoyce93 View Post
I can't get a voltmeter on the connector, it's just too small. Here is a complete description of the symptoms my car is experiencing. If I disconnect the monovalve, instant heat, very hot. With the monovalve connected after startup I get a very slight increase in heat eventually. However if I stop the car for a few minutes ( to get diesel for example) when I start back up, much more heat is blowing through the fan! If I continue to drive for another 30 minutes or so, all of a sudden the heat drops back down again! It doesn't matter whether I have the setting on defrost, economy or whatever, the results are the same. Thanks for you help!
You don't have to have the connector plugged in to the monovalve to test the signal. Just pull the two-wire connector off and stick the voltmeter probes in the sockets.

Once the signal is verifed, it sounds like you may be having a problem with the temperature control. Either the module is not cycling the monvalve correctly, or the module is getting bad input from the cabin temperature sensor, the heater box sensor, or the temperature selection wheel.I'm no inclining toward the sensors though. The monovale should be commanded to supply heat if the wheel is turned to the click stop at full heat. Check the voltage on that connector with the wheel at the full stop, on economy.
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