How to Change the Battery on a 2008 GMC Acadia. The 2008 GMC Acadia is a cross between a minivan and an SUV. It has plenty of seating and almost no open space in the engine compartment. Due to the compact front end, GMC had to store the battery in a small compartment that is built into the floor pan. GMC made getting to the battery easy, and replacement is just as simple as replacing an under-hood battery.
Open the rear door and remove the floor mat. Find the battery cover that is attached to the floorboard behind the passenger seat. Remove the retaining screw with a T20 Torx driver. Lift the battery cover and place it aside.
Loosen the negative battery terminal with a socket and ratchet. Pull the negative battery cable off the battery and place it aside. Squeeze the locking tabs and disconnect the wiring harness from the battery current sensor and negative battery cable.
Squeeze the locking tab and disconnect the wiring harness from the positive battery cable. Position the wiring harness and electrical connectors aside. Lift the positive battery terminal cover and loosen the terminal nut. Remove the positive battery cable and set it away from the battery.
Find the battery hold-down bracket. It is on the side of the battery that faces the rear of the vehicle. Remove the hold-down bolt with a socket, ratchet and 9-inch ratchet extension. Lift the hold-down bracket and hold-down bolt out of the battery compartment.
Pull the vent hose off of the battery. Lift the vent hose grommet out of the battery compartment and set it aside. Firmly grab the battery and lift it out of the battery storage compartment.
Set a new battery into the battery compartment. The battery terminals should be facing the rear of the vehicle. Set the hold down bracket into place and install the bracket bolt. Tighten the hold down bolt to 18 foot-pounds with a socket, 9-inch ratchet extension and torque wrench.
Connect the battery vent hose to the nipple on the side of the battery. Slide the vent hose grommet into place in the battery compartment. Connect the positive battery cable and tighten the nut to 80 inch-pounds. Close the positive battery cable cover.
Connect the wiring harness electrical connectors to the positive battery cable, negative battery cable and battery current sensor. Pull on each connector to make sure they are properly connected. Connect the negative battery cable and tighten the nut to 89 inch-pounds.
Set the battery cover over the battery compartment and tighten the retaining screw. Install the floor mat.