I have a 2007 Ford Expedition EL with the following problem:
1. The exterior or ambient temperature indicator, as located on the dash air condition unit with a button "EXT", gives increasing higher tempartures, 20 degrees much higher as the outside temperature really is,
2. The interior temperature gets colder and colder. I have to increase the heater temperature by 10 degrees above normal temperatures to keep it warm inside.
Is there a problem with the ambient air temperature sensor (located behind the front grill) ? And would the indicated higher outside temparture automatically result in the lower inside temperature, the AC-unit "thinking" that - because of the assumed hotter outside air - more cold air should be generated for the interior of the car ?
I hope somebody can help me out. Over here in the Netherlands we do not have much Ford truck experts ...
That's a good question. I don't think the inside ac would be affected by the outside temp reading. It would be strange both sensors went bad at the same time though.
I know that the automatic air systems do use the ambient light sensor to help adjust the temp inside. I am also 99% sure (and 100% on GM) that they use the outside air temp to adjust and blend the inside temp.
I would break out the multi meter and check the voltage range on the sensor to see what you are getting, if it's wacked then you need to replace the outside temp sensor. If it were me and I'm fat thus hate to sweat, I would stop by autozone on the way home and pick up the outside air temp sensor and swap it out.
My silverados is slow to respond these days with about 250,000 miles on it in the rain the OAT will show the 60s even when it's 95 degrees out, once it dried out it's fine and within 1* of acutal.
Cliff notes: Change outside air temp sensor and see what happens. I'd be that is the culp.