Talk to a Mustang Expert
Mon - Sun, 8:30 AM EST - 11:00 PM EST

Free Shipping On Orders Over $49. Details

Splice-In Mustang Lightbar Switch - Installation Instructions

Installation Time

60 minutes

Tools Required
  • 10mm Socket (94-02 Rear Seat Removal)
  • 18mm Socket (03-04 Rear Seat Removal)
  • Socket Wrenches to Fit Sockets Listed Above
  • Socket Wrench Extension (3 inch)
  • Flathead Screwdriver
  • Pliers
  • Wire Cutters
  • Wire Strippers
  • Volt Meter


1. The first step is to get the rear seat out of the way. Start with the seat bottom. Find the retainers; they are about halfway between the middle of the seat and the side of the seat bottom. There’s one on each side of the seat bottom, and use a flathead screwdriver to release the seat.

2. It’s easy to see how the retainer operates once the seat bottom is removed. You’ll push the plastic button in with the head of the screwdriver.

3. Use a 10mm socket (99-02), 18mm (03-04), to remove the seat back bolts. There are two bolts holding the seat back in place, one at each lower corner of the seat back.

4. At both top corners of the seat back, there’s a tab that fits into the car. Pull up on each side of the seat back to free these tabs.

5. The middle of the seat back is held by a bracket that fits into the car. Once the tabs are free, push the seat back down to free it from the car.

6. With the seat back removed, you can see the tab that secures the bracket on the seat.

7. Now remove the cluster of wires found in the channel under the rear seat, on the driver’s side of the car. You want to find the wire that supplies 12 volts to the third brake light, when the pedal is pressed. You can look at the third brake light in the trunk to help determine which two wires are routed to the light, and then use a volt meter to determine which wire carries the voltage. The color of the wires will vary between the various models. In a 2000 Mustang this should be the green wire.

8. Use a quick-splice connector to connect the black wire of the Light Bar Switch to the 12-volt brake light wire. Notice that the quick-splice has one channel that is open and one that is closed. Place the 12-volt brake wire in the open channel and the black wire from the Light Bar Switch in the closed channel. Use a pair of Channel Locks, or similar pliers, to fully press the metal tab into the connector. Do not use standard needle nose pliers as they can crush the connector. Make sure you install the quick splice connector far enough down that you can return all of the factory wires back into the channel.

9. Once the metal tab is in the connector, snap the cover into place over the metal tab.

10. The white wire for the Light Bar Switch is used if you want to disable the factory third brake light while the convertible top is lowered, using only the light bar’s brake light. If this is the desired operation, you will cut the 12-volt wire for the third brake light, and connect the black wire from the Light Bar Switch to the portion running to the front of the car, and the white wire to the light going to the factory third brake light. Keep in mind that operating the third brake light in this manner may not be legal in some states. I chose to not use the white wire, and capped it off with a wire nut. Having both third brake lights in operation will hopefully serve as a better warning for drivers behind me. I’m not fond of the thought of being rear-ended.

11. Now connect the blue wire from the Light Bar Switch to the power wire from the light bar. If you have installed a CDC light bar, this will be the wire with the red stripe on it. Strip the wires if necessary, and then twist them together. Then twist a wire nut onto these wires to secure them all together. Make sure there is no bare wire exposed below the wire nut, and ensure that the wire nut is securely in place.

12. Now find the plug that controls the top motor.

13. The plug resides behind the rear seat. Use a flathead screwdriver to slightly pry the tab on the plug and free it.

14. Use some of the supplied wire to extend the red and yellow wires. I opted to use the wire with the red stripe to extend the red wire, and the black wire to extend the yellow wire. Strip the wires as necessary, and cap them off with two of the supplied wire nuts.

15. Use a volt meter to see which of the wires on the plug shows 12-volts when the top is being raised. The Light Bar Switch’s red wire connects to the wire that shows 12-volts when the top being raised. Connect the Light Bar Switch’s red wire to the 12-volt wire for the top motor with a quick splice. For a 94-04 Mustang, this should be the red wire on the plug for the top motor.

16. Using another quick splice, connect the yellow Light Bar Switch wire to the other top motor wire. For a 94-04 Mustang, this should be a yellow wire.

17. Reconnect the plug, and remount it if it was removed.

18. If your light bar has not previously been wired, you’ll want to ground the other wire coming from the light bar. The Light Bar Switch does not come with a connector to use for grounding purposes, as the manufacturer assumes that most owners will already have completed this task.

19. Secure the Light Bar Switch wires alongside the wires for the top motor.

20. Secure the factory wires back into the channel, and rewrap the channel with electrical tape to hold them into place.

21. Use another wire tie to secure the Module for the Light Bar Switch to the bundle of wires running under the seat.

22. Finally reinstall the rear seat back and bottom, and test operation of your newly installed Light Bar Switch. The brake light on the bar should function with the top down and the brake pressed. When the top is up, and the brake pedal pressed, the light should not function. You may have to raise and lower the top once for the Light Bar Switch module to start functioning properly, once it does you’re all set to go!

Installation instructions provided by AmericanMuscle customer Eric Hege 7.6.09

Related Guides