In the storage compartment in the floor behind the rear seats. You have to fold down the seats to get to it. And go to the Chrysler website for an owner's manual.
The Chrysler Pacifica offers FIVE folding seats.
between the seats, under the console
It is under the console, between the front seats.
There wasn't a 2015 Chrysler Pacifica. In 2015 there was a Chrysler Town and Country. It's spare , if equipped, is located under the van below the front row seats. Most did not come with a spare tire.
The jack for a 2004 Pacifica is located under the storage compartment in the back of the rear most seats. Open the storage compartment lid, then lift out the storage tray.
It is under the console, between the front seats.It is under the console, between the front seats.
open liftgate, look down, open compartment behind last row o seats, pull up carpet in compartment, ta-da
Check behind the second row seating. There's a storage area, but you have to pull up on it from the sides. I have to lower the seats to get access to it in mine.
The Chrysler 300M was produced from 1999-2004. Leather trim was a standard feature, as well as heated front seats and memory controls for the driver.
The seats will not bolt up or plug in.
I think it depend on the configuration of your Pacifica. If you have the 3rd row seat, I think it is under the luggage storage area. I have the 2nd seat row only and I have to fold down the 2nd row seats. There is a compartment in the storage area up against the backs of the second row seats (in down position). Lift up the door of that compartment and the jack should be in that compartment on the passanger side of the vehicle.