How To Install '69 LED Sequential Taillights

Next remove the large rubber gasket to access the screws underneath.

With the gasket removed, detach the six screws to allow removal of the lens from the housing.

Separate the lens from the housing, which is where the LED module will be placed.

Remove the 1157 light bulb from the socket by pushing in and twisting to the left.

This is where it gets a little trickier with a '69 Mustang. The LED module has to be plugged into the socket while it's inside the housing, and the whole thing needs to be reassembled while connected to the harness inside the trunk. It's not too difficult, but be careful not to pull too hard on the wiring harness while putting everything back together. Plug the LED module in place as shown here by pushing the module down and turning to the right.

The installed module should look like this. To get the module straight inside the housing, the angle can be adjusted by loosening the screw in the center of the circuit board and rotating the module.

Place the lens back onto the housing, then reinstall and securely tighten the screws.

Be sure to securely press the gasket back into its original location around the entire circumference of the taillight housing.

Reinstall the housing. Again, remember you have to do steps 8-11 while the housing is attached to the wiring harness inside the trunk, so be careful not to pull the wires too hard while putting the taillights back together.

Reinstall the four nuts that hold the housing in place, and tighten them securely with a 1/4-inch-drive ratchet and the correct socket. On our car, one of the sockets was somewhat loose in the housing, which caused the LED module to be off-center in the housing. We easily solved this issue by securing the socket (and LED module) inside the housing with four small pieces of duct tape.

Moving inside the car, locate the turn-signal flasher under the dash. To help locate it, engage the turn signal so you can hear it clicking. Remove the existing flasher unit, carefully but firmly pulling it out by hand.

Installing the flasher module is easy, in part because it's already equipped with the correct plugs. Plug it into the factory harness in place of the stock flasher unit. Plug the green wire of the module to the car's green wire and the red wire of the module to the car's yellow/orange wire.

To complete the installation, connect the black wire of the flasher module to a suitable ground under the dash. We used one of the bolts under the glovebox door to provide a proper electrical ground.