The temperature readings seem a little high on the thermometer checks even at idle unless the ambient air was over 90 degs when this was checked. What do you have to check the system with? Do you have gages? Do you have maybe an infer red thermometer?
How often is ac compressor cycling on at off ?About how many secs on and how many off?
What is ambient temp around the vehicle when these checks are made? Is cooling fan running with ac on?
The service tech at the ford place inserted a thermometer in the vent-He stated that the reading 50 to 60 degrees was the range it should be. I went out and bought one of these thermometers and did the same check the service tech did. At idle and normal highway driving the AC cools just fine; however, when I tow my pontoon boat or when the rpms reach 4200, the ac starts to blow warm. Ambient temp at time of check was 82 degrees.around the vehicle.Compressor is cycling on and off however not sure how often (I will check) and get back to you
It should cool lower than 50 to 60 degrees at 82 deg ambient temp. It should get down around 45 degrees or lower on max AC at that temp.
Ford does have a technical service bulletin out for a very similar concern though. The TSB number is 08-23-6 here are the specifics on it.
Some 2005-2008 F-150 and 2006-2008 Mark LT vehicles equipped with Electronic Automatic Temperature Control (EATC) may exhibit intermittent periods of warm air output in Auto mode with the temperature control set between 68-72 degrees Fahrenheit (18-22 degrees Celsius). Some 2005-2008 F-150 vehicles equipped with Electronic Manual Temperature Control (EMTC) may exhibit periods where the cabin temperature cannot be maintained with the control knob. Some customers may also complain the heat cannot be reduced without rotating the control knob well into the Cool/Blue range.
Refer to the following Service Procedure to correct the condition.
The condition may be caused by a faulty temperature blend door actuator.
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