Edmunds Answers



  • laltazan 08/25/11 4:26 pm PST

    Here's a few other things you might look at. Check the two heater hoses and see if they are hot. If both are hot, the problem is with the blend door/evaporator case. If one is hot and the other is cool, the heater core is plugged. If both are cool, check the water pump. The impeller can break and plug the passage to the heater, as well as cut circulation in the system.

  • Stever@Edmunds 08/28/11 7:34 am PST

    You can continue in this thread by clicking the Answer this Question button and that will help keep all the information in one spot. Thanks!

  • maven0613 09/04/11 1:39 pm PST

    CORRECTION: Blend door actuator replaced. Vacuum lines checked. All works normally now but still no defrost and heat comes out of a/c vents. Now what am I missing?

  • maven0613 09/05/11 12:18 am PST

    ****UPDATE:****The dash is out again so I checked vacuum lines manually and the floor/defrost door, panel door (heater air damper door), and the recirculating air door all respond.

    I have diagnostics and instructions for a Heater Control Cable replacement but there is not one attached to the EATC module nor is there a place that one would go so how does the EATC decide "defrost only" on mannual override when there is no dedicated defrost vacuum line or cable?

    Also, is heat supposed to come out of the panel vents or just the floor and the defrost vents? When it is on "floor" on manual override the heat comes out of the panel vents also even when you select 60 degrees on the temperature selector.

    Thanks so much for replying. It's starting to get cold here (Colorado) and I'm in panic mode as I'm traveling a lot between here and Wyoming and need her fixed so I can work. One more day off - need to find it soon!


  • maven0613 09/05/11 7:34 am PST

    Now I am looking for the interior temperature sensor location as there is some erratic behavior. When the heater gets hot then it suddenly gets lower and when the a/c gets cold then it suddenly gets warmer. It's like the interior air temperature sensor is in the airflow somewhere and is "correcting" the temperature it's calling for.

    Still no air out of defrost ever.

  • maven0613 09/13/11 7:39 am PST

    **UPDATE 09/13/2011**

    After blend door actuator replacement the A/C appears to work normally. The heating system still has the following problems:


    On any setting the heat at max (90 deg) does not heat the interior to more than approx upper 60s. A/C temp setting to actual appears correct but heat temp setting to actual is about 10-15 degrees off. Air is just lukewarm when asking for heat.

    Even at 90 deg setting when switching to defrost it blows cold air only out the windshield vents.

    All air all the time blows out of panel vents and must be manually redirected to floor or defrost by shutting the panel vents. But this may be just how the system operates (?)

    Blower appears very low at all settings particularly defrost. It does go higher at manual (turn wheel) but seems low to me.

    When switching to vent from any heat setting the air appears to be slightly warmer.

    Covering the solar sensor changes nothing regarding defrost but I still don’t know if the solar sensor even has anything to do with the EATC.

    What am I missing now?


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