Sequential Tail Light Mod ?s

Taken from: http://mustangii.net/sequential_faq.asp (I usually wouldn't, but MustangII.net has been down a lot over the past year, sometimes for months at a time, and it would suck to lose access to the article again. If Tim or one of the staffers over there asks me to delete this, I will.)

Mustang II Sequential Taillight Conversion by Rob Royster
This conversion is fairly simple and straightforward. Upon completion you will have 6 taillights, 6 brake lights and sequential turnsignals. Yes, when your signal is on you will have 3 brake lights lit on the opposite side when the brakes are applied. (Note - This conversion can be performed whether you've modified your taillight lenses to all reds or not, but will look goofy if you haven't done so).

Here is my parts list for my sequential conversion:

1- Set of Modified Tail Lamp Assemblies All red lenses, center lamp housing modified for 1 socket

1- Web Electric Products #STS-1 Universal Sequential Taillight Kit

1- Reese Towing Trailer Converter Kit #74209 Kit is designed specifically for cars with separate turn signal and brake light circuits.

1- #536 Heavy Duty Flasher For 1 to 6 bulbs in the circuit

2- Calterm #08554 Ford Socket Assemblies Color coded 3-wire bulb socket for #1157 bulbs

2- 1157 Long Life Bulbs

2- Tiger Accessory Group "Baja Tough" Heavy Duty Relays #DF005 Externally grounded 5-Prong relay

Misc wire connectors, wire and electrical tape

After removing your cargo/trunk panels to access your tail/brake light wiring harness, the easiest way to start the conversion is to install one component at a time. You'll be using the wiring instructions from the trailer converter, the relays and the STS-1 kit.

IMPORTANT - Disconnect your battery ground before starting!

1. On your wiring harness locate and label the following wires going to your sockets (for ease and less confusion I left my sockets installed): Brown - Tail lights. Black - Ground. Light Green - Brake. Light Blue - Right Turnsignal. Light Green/Orange Stripe - Left Turnsignal. - NOTE - These color codes are based on the wiring schematic for a 1978 model. Your wire colors may differ slightly for 1974 - 1977 models.

2. Using your trailer converter wiring diagram as your guide cut and splice one wire at a time and connect your factory harness to the Car Side of the converter. Your splices should be connected as follows: Right Turn Signal, Light Blue to Green. Brake Lights, Light Green to Red - NOTE - You only need to splice 1 of the 4 Brake Light wires to the trailer converter for this installation. Left Turn Signal, Light Green/Orange Stripe to Yellow. Tail Lights, Brown to Brown. - NOTE - You only need to connect 1 of the 4 Tail Light wires to the trailer converter for this installation. Factory Wiring Harness Ground, Black to White. - NOTE - You can either ground the White wire or splice into the Factory Harness ground, your choice.

3. Remove and replace your 2 wire turnsignal sockets with the new 3-wire color coded sockets. The only wire you'll be connecting at this point will be the ground wire (Black), and install your new bulbs. Install your new sockets. - NOTE - All of your light sockets should be connected to ground at this point. Black to Black.

4. Connect/Splice all 6 tail light wires to the trailer side of your converter, Brown to Brown.

5. Connect the trailer converter trailer side ground wire to a metal ground. White to Ground. - NOTE - Not sure if this is really needed or not, but I did this step.

6. Connect the Right Turn/Stop wire from the trailer side of the converter to the Switch input on one of your relays, Green to Relay.

7. Connect a new wire from one of the output side terminals on the relay (the relays I used have 2 output terminal), to your Light Green wire on your 1st, or inner light socket (Right Taillight Assembly). All the wires to this socket should now be connected.

IMPORTANT - The Green or Light Green wires from the middle and outer sockets should not be connected at this point

8. Connect a new ground wire from the relay to ground (I used the factory harness ground).

9. Connect the Left Turn/Stop wire from the trailer side of the converter to the Switch input on your second relay, Yellow to Relay. Repeat steps 7 and 8 for the left Tail Light Assembly.

10. Connect and Run a wire from a constant 12V power source (battery), to the power input terminal on both relays. - NOTE - This is the most time consuming part of the installation unless you've relocated your battery to the rear of the car as some of us have.

11. Using the instructions that came with your STS-1 Kit and the supplied quick splice connectors, connect the Red wire of the fist STS module to the Output wire from the relay that goes to your Inner Right Turn Signal Socket.

12. Use another quick splice connecter and connect the module's BLACK ground wire to your factory wiring harness ground.

13. Connect the White wire from the STS module to the Green or Light Green wire of your Middle T/S Socket. All 3 socket wires should now be connected.

14. Connect the Blue wire from the STS module to the Green or Light Green wire of your Outer T/S Socket. All 3 socket wires should now be connected.

15. Repeat steps 11, 12, 13, and 14 for the other side.

16. Remove your existing turnsignal flasher and replace it with the #536 flasher. You're allowed to cuss the Ford Engineers who determined the fuse panel's location for our cars.

Last step. Double check your connections then reconnect your battery. Enjoy your new lights!

All credit to Rob Royster for writing it, and MustangII.net for hosting it.