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Climate Control-one sided heat

1590 Views 8 Replies 4 Participants Last post by  mannfrm
Good Morning-

Texas weather has been nice till this week when we got our first freezing temps.
My 1994 w140 climate control was not up to heating the cabin sufficiently. I ran the sensor value test.


est Step Sensor Value Display
1 73 In-car temperature sensor w/ aspirator blower (B10/4)
2 72 Outside temperature sensor (B10/5)
3 86 Left heater core temperature sensor (B10/2)*
4 87 Right heater core temperature sensor (B10/3)*
5 35 Evaporator temperature sensor (B10/6)
6 87 Coolant temperature sensor (B10/8)*
7 11 Refrigerant pressure in bar (06 = 6 bar)
8 14 Blower control voltage from B(min) - 60(max)
9 20 Software status

Also, performed flap test and found 3 to 4 of primarily driver side flaps did not seem to operate by ear. So, I turned heater on and checked both sides of compartment for air flow. I found that I was not receiving heat from most driver side vents and if any air flow was found, it was non-heated air. Passenger side vents were operating and I could feel heat. Turned on the red button on center vent and received heated air on passenger side but none on driver side.

My questions are:
-the above sensor values look correct except #5. Do I have a evaporator sensor out?
-Is the non-performing driver side attributable to a non-functioning duo-valve or possibly a Y11 vacuum block malfunction?

Those are my questions from reading through the archives. Any help will be appreciated.

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