GT Concepts 2005-2008 Mustang Plug n Play Tail Light Harness Installation Instructions

Step 1
Verify that all rear lamps are functioning properly.
Remove the trunk rear trim panel by removing four push rivets: Lift out the center part of the rivet then pull the rivet out.
Remove two Torx retainers with a T-30 or flat screwdriver.

Step 2
Remove the three tail lamp assembly retaining nuts using an 11mm or 7/16" socket or wrench.
Beneath one of the nuts there may be a flat assembly nut.
Insert knife blade under assembly nut and pry apart. Insert screwdriver between gap and break assembly nut. Remove with pliers and discard.

Step 3
Disconnect tail light wiring harness by pressing the locking tab then pulling the connector apart.

Step 4
Remove tail lamp assembly. Avoid paint scratches from the retaining studs.
Pull out rubber grommet and remove the harness.
Place the tail lamp assembly face down inside the trunk.
Remove the four lamp sockets, turn counter clockwise then lift out. Remove old harness.
Swap out bulbs from the old harness to the new.

Step 5
Install new harness into the tail light housing. The lamp sockets are labeled 1, 2 & 3 corresponding to the L1-inner, L2-middle and L3-outer positions.
Align the small tab on the reverse lamp socket with the small slot in the housing and turn clockwise, it may be tight.
Insert the gray harness connector thru the body hole and install grommet.
Reinstall tail light assembly. Avoid paint scratches from the retaining studs.
Reconnect the harness connector.
Repeat steps 2 through 5 for the other side.

Step 6
Switch on hazard flasher. Verify lamps for proper inner, middle and outer lighting sequence. Swap lamp sockets if necessary. Switch off hazard flasher.
Switch on parking lamps. Verify lamp operation. Switch off parking lamps.
Engage parking brake, switch ignition on but do not start, place gear selector into reverse. Verify reverse lamp operation.
Return gear selector to park. Switch ignition off.
Depress the brake pedal and verify that all six lamps and the center mount brake light are lit.

Step 7
Install the three nuts on each tail light assembly. Verify that the tail light assembly is fully seated or the housing may crack when tightened. Do not over tighten.
Reinstall rear trim panel. Lift spare tire cover up over the lower rear trim panel tabs.
Lift the trim panel up at the trunk latch and slide trim panel over the latch.
Reinstall push rivets and Torx retainers.

GT Concepts
505 4th St SE
Childersburg, AL 35044
Contact us at: CustomerService@gtconcepts.net