Most likely the vacuum hose is disconnected or broken.
Does your cruise control work?
Check this out :
http://www.jeepforum.com/forum/f9/fan-always-blows-defrost-selector-doesnt-work-830241/
If you have the defroster in the on position the ac will do that.
"how do you change a throttle position sensor on a 1998 jeep grand Cherokee?" could someone without any experience do it?
it is what keeps ur cranks shaft timed and in the right position
Yes.
4liter is in distributor.
Throttle position sensor out of range.
In the underside on the far left
The sensor is not adjustable.
A/C or defroster on Relay stuck in closed position Temperature sensor not sensing proper temperature
faulty throttle position sensor?
The crankshaft position sensor is bolted to the bell housing of a 96 Grand Cherokee. It is at the top of the bell housing, just on the drivers side on a 4.0 L and on the passenger side on a V8.
Assuming that the fuel tank is empty--float should be at lowest position