Thought I'd share my install of the PIAA 8511 115db 400 Hz and 500 Hz horns. I was not happy with the sound of the stock horn, almost embarrassed to use it. And I haven't seen any install guides here that I liked, so I documented my install.
This is as installed on my 2012 JKU
- PIAA 8511 Horns, available from multiple retailers.
- 5" of 1/8 inch aluminum bar (available at Home Depot, in 2 foot length)
- 3, 3/8" hex bolt, 1" long
- 3, 3/8 nuts
- 3, 3/8 locking washers
- 3, 3/8 washers
- 2, Wire tap connectors (I used these, bought at Home Depot Amazon.com: Quick Splice Wire Tap Connector 22-18 Gauge (Red) - 100 Pack: Automotive
Remove the old horn.
Take the two wires that came with the horn, and cut off the u-shape wire connector (not the spade end that plugs onto the horn, we need that end). Use the wire tap connectors to one wire to each of the factory horn wires. DO NOT cut off the factory horn connectors, those will still be used to connect one of the horns. These included wires tapped into the factory wires will connect the second horn. This is how the instructions that came with the horns suggested to wire them.
: Find out which wire is positive. On mine, it was the grey wire with yellow strip. To check, connect a volt meter, set to measure voltage. Push your horn, and if you get a +12v, you've got the polarity right. If you get -12v, you've got it backwards. Mark the wire appropriately.
Cut your aluminum bar to 5" and drill holes approximately as shown below. Drill the holes just large enough for the 3/8" bolts. I also rounded of the edged, and painted it black. I also painted the nuts, bolts, and washers black too.
These pictures show how I'm going to attached the horns to the bar. The top hole on the bar is going to bolt to an existing hole in the engine bay, shown below (2nd picture).
Bolt one of the horns to the lower, bottom hole (as noted in the first picture). Don't tighten it all the way, we'll get it lined up in place first. Note I do not remove the dust cover on the lower horn, but will on the upper horn. Also I had to widen the holes on the horns slightly to accommodate the 3/8" bolt.
Line up the top hole on the bar with the hole in the Jeep. Place a bolt in the hole if it helps. Adjust the lower horn angled down as far as possible, to keep enough room for the second horn. Note you might want to connect the factory wires, as that may affect the position of the horn. Once your happy, carefully remove the horn and bar, and tighten that horn down good and tight.
After tightening the first, lower horn, reinstall back in the Jeep, and connect the factory horn connectors to this horn. Connect the positive to the top connector on the horn (as you are looking at it reading the PIAA label). Connect the negative to the lower connector. Then bolt the bar to the Jeep and tighten it down.
Room for Improvement
: It may be better to move that middle hole down (or flip the bar), so that the bar can be removed without removing the top horn (or so the bar can be installed with both horns attached before hand).
I removed the dust cover from the second (upper) horn (shown below, horn on left), as there wasn't enough room for it. Its aimed up, so should stay relatively clean. The factory horn didn't have any cover, so I figure its probably okay.
Once the bar is attached to the Jeep, install the second horn and connectors (that were included, and tapped into the factory wires). Same rule applies on polarity, positive on the top most connector on the horn. I used some pliers to make the connectors tighter, so they wouldn't easily slip off.
Here is a video of the difference for me:
Now you can honk without people laughing at you. Enjoy!