Should you be unlucky enough to have the headlamp bulb in your Mercury Cougar burn out, you can replace it yourself. This job doesn't require any mechanical expertise, but you'll need to get the appropriate replacement bulb before starting. These instructions only apply to models made after 1989.
Remove the center cover and the screws attached to the radiator grille. Pull the radiator grille out of the engine compartment and set it on the ground.
Use a T30 Torx screwdriver to remove the two primary retaining screws from the headlight assembly. Make a note of each screw's original location--they're not interchangeable, so you'll need to put them back in the right slot to reassemble the light.
Draw the headlamp assembly away from the car and then disconnect the electrical wiring connector.
Release the wire clip on the back of the headlight assembly and remove the cover.
Disconnect headlight electrical connector and turn the bulb socket counterclockwise to remove it from the assembly. Install the new bulb, replace the cover and reattach the electrical connector.
Reconnect the headlight assembly wiring connector. Test the new bulb to make sure it works before replacing the retaining screws and radiator grille.
Remove the electrical connector from back of the bulb with a quick rearward tug.
Turn the retaining ring counterclockwise and slide it off its plastic base. Keep the ring in your pocket or in a small bag for safekeeping.
Pull the old bulb straight out of the socket and replace it with the new one. Push the bulb in until its plastic base touches the back of the socket.
Twist the retaining ring onto the socket base and reattach the electrical connector.
Test the new bulb to make sure it works before closing the hood.
