Second Horn Installation

This is one of the first electrical mods I made to our new Iceberg FJ Cruiser.

The FJ Cruiser is wired for a second horn. However, the wiring harness for the horn is located behind the washer fluid reservoir. I have written instruction on installing a second horn in front of the radiator using the factory harness for the second horn.

Optional Horn Relocation

I was starting on implementing my auxiliary  power fuse/distribution block today and needed the location of the optional horn for components used for my auxiliary  power system. I pulled up the electrical diagram and found that the horn wire is GR-B (Grey/Black).  Using this information I was able to trace the wire back through the wiring harness and move the horn the what I feel is a better location, in front of the radiator with the other horn. Included here are a few picture and some instructions on how I did this modification to my FJ.  (Please note that messing with your FJ electrical system should not be taken lightly, you just might toast something.) Before working on any part of your electrical system always disconnect the battery.

Figure 1 – Horn wiring diagram


Step 1: Remove the option horn from its location at the left rear side of the engine compartment.

Step 2: Remove the bracket from the horn and flatten the bends out.

Step 3: Shorten the bracket by about ¾” and drill a hole in it that will accommodate the bolt.

Figure 2 – Horn bracket

Step 4: Reattach bracket to the horn and mount it in the new location. There is a threaded stud located about 6” from the left edge of the radiator in the top bar. Mount the  horn facing down in this location.

Figure 3 – Horn mounted in new location


Figure 4 – Another picture of horn in new location

Step 4: Locate the wiring harness at the left upper side of the radiator, open the loom and pull the wires out. You will need to remove an electrical tape wrap from the wires.

Figure 5 – Wiring harness


Step 5: Locate the Grey/Black wire and cut. (Be sure you cut the correct wire. I verified it with an Ohm meter.)

Figure 6 – Horn wire location to be cut

Step 6: Cut the original horn connector off next to the harness so you can reuse the connector at the new location.

Step 7: Remove the trim panel that covers the space between the radiator and the bar in front of it. To remove the clips pry out the center and the clips will pull out. Be careful I broke 2 clips  that I now need to replace.

Step 8: The harness is held in place by 2 clips that can be removed from the side facing the front. Once these clips are pushed back trough you can pull the harness up between the AC condenser and the cross bar.

Step 9: Open the wire loom and locate the Grey/Black wire and pull the wire through from the left were you cut it.

Figure 7 – Horn wire being pulled out


Step 10: Reattach the horn connector in the new location. I added a plastic sheath to cover most of the wire. I tried to disassemble the connector so I could attach the wire directly with no splice but even with the lock remove I could not get it apart.

Figure 8 – Connector reattached

Step 11: Tape the point where the wire comes out of the wire loom.

Figure 9 – Taping the wire loom

Step 12: Plug the connector into the horn.

Step 13: Reattach the wire loom behind the cross bar.

Step 14: Replace the trim panel.

Step 15: Be sure the wires are stuffed back into the wire loom next to the radiator.

Step 16: Reattach Battery.

Step 17: Test your horn.



Tomas has lived in Colorado since age 5. Having grown up on the Western Slope of Colorado lots of time was spent in the Desert Southwest. Tomas' father introduced him to the love of 4 wheeling at an early age in the high mountains around Aspen, Colorado. While an avid Mountain Biker, Tomas and his Family enjoy adventures in the mountains and desert in the remote locations that can only be reached by 4wd. Day hikes are always a must when on the family trips. While enjoying outdoor activities he wants to share his love as a certified 4wd trainer and ski instructor. Tomas also enjoys caving and cave exploration. Tomas currently resides in Colorado Springs. 

  3 comments for “Second Horn Installation

  1. dale durham
    August 19, 2010 at 9:10 PM

    Great write up!

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