Originally Posted by DieselD
Sounds like you have a a vacuum leak somewhere, all those things run off of vacuum provided from the manifold.
Start checking the lines. And make sure you have a vacuum reservoir ball, should be behind the front bumper on the passenger side.
The trans switch changes the way it shifts. Just keep it on power.
Power trans makes the trans shift a little earlier, your mpg should stay the same I've heard of people getting better mpg on power mode, I personally get the same mpg in power or comfort.
It definitely sounds like you have a vacuum leak both the defrost and cruise control run off vacuum provided by the ball mentioned above, it's very common for those lines to break. Brakes work off the vacuum from the intake manifold as well so start poking you head around and listening for a hissing sound while the engine is on.