I've noticed lately that as soon as I turn the ac on it smells real bad for the first min and then goes away. It just started this maybe a month ago. The other thing I've always wondered is why does it go to the feet when you first turn the jeep on and then a few secs later go towards the top vents when I had it set to that already.
I don't know if this is related but when it's sat over night it makes a humming sound for a few secs on and off and then stops. This is even with out the ac on. It kinda sound like a small primer motor or something