The Idle Air Control (IAC) valve on a 1991 Dodge Caravan 3.3L engine is located on the throttle body. It's a small, usually cylindrical, valve mounted directly to the throttle body itself. You'll need to look closely at the throttle body; it's typically near the top or side, connected by a single electrical connector.
To be certain, you might want to consult a repair manual specific to your 1991 Dodge Caravan 3.3L. A diagram will show the exact location.
