I thought I was losing my mind this morning when I stumbled across this, but I had another big swig of coffee and by-golly it was true. I noticed a substantial difference in temperature coming from the air vents (on A/C) between the two drivers and the two passenger vents on my 2001 F150 5.4.

It's when I have the thermostat around 10 or 11 o'clock (where it stays allot) that it is very noticeable. At 10 o'clock on the dial it's nice, cool, and comfy on my side and almost warm on passenger side. However when my thermostat is pegged to cold, it is hardly noticeable, but I would freeze. I'm going to dig-out my little digital thermometer and confirm the temp spread, but I would say we are talking about 10 degrees at least. Has anyone else ever noticed this. Could this be some kind of feature for varying the temperature to passenger?

Seems weird. Any ideas?

Thanks
Reid