rodg wrote:I finally bought the Stebel Brio dual air horns.... they are super loud. I installed it between the radiator and the grille. However, I am having issues with the wiring. I can't seem to get it working. I disconnected the OEM horns and wanted to tap it to the OEM horn harness but no luck. I tried following the wiring diagram using the supplied relay but when I get to wiring connection to the OEM harness it won't work. Maybe some expert here can help me out.
I saw a posting on the NORA website from a guy who put in PIAA replacement horns in an Xterra, which got me thinking of your problem.
It seems you're not experienced with electronics/electrical work. Please don't take this personally, because it's a technical skill most people don't know, and many who think they do know, only know enough to cause damage. But, ideally, you should have someone to provide you with hands-on assistance to avoid causing potentially expensive damage to your Pathfinder's electrical system. At best, if you wire things incorrectly
you could burn-up the horn relay and the cable harness between the relay and the horn before the 15-Amp fuse blows (look at all those other wires in the bundle). At worst a short caused by the relay frying or horn wiring harness melting could short to other wiring buses and
could even start a fire. The results could be hundreds, maybe thousands of dollars in damage.
Now that I've warned you, here is what I believe needs to be done:
According to the R51 Pathfinder service manual, you want to use Stebel's "hot lead" installation instructions. While the horn button uses ground signaling, this activates the horn relay to provide +12V DC to the horn itself.
Note: You will lose your radio and clock settings during this process, as well as any driver position memory settings, if you're vehicle is so equipped.
Also Note: Use the appropriate size and type of terminals (connectors) on each end of the wires. Don't just wrap the wires around the connections. Use slip-on terminals rated for the correct wire size to connect with the relay and horn. Use ring (circular) or half-moon (semi-circular) connectors to hook-up to the battery and the chassis ground. Double-crimp these terminals, if space permits, with at least 1/4" between crimps to prevent the wires from coming loose, but don't overcrimp or use excessive force to pierce the insulation or cause mechanical failure of the internal contact barrel.
- Disconnect the POSITIVE (+) lead from your battery.
- The GREEN wire on the horn connector (at least it's labeled "G" in the manual) provides the +12V to activate the horn. Connect that to pin "88" on the relay.
- The BLACK wire on the horn connector (labeled "B" in the manual) is ground. Connect this to pin "85" of the relay.
- Route a 10 AWG (10 Gauge) wire with in-line 20 Amp fuse from your battery's POSITIVE (+) terminal to pin "30" on the relay. do NOT connect this wire at this time! Make sure to secure the wire so it cannot come in contact with sharp, moving or vibrating parts.
DAMN IMPORTANT: You MUST install the illustrated 20 Amp fuse on this wire. The wire gauge MUST be 10 AWG stranded wire designed for under-hood, automotive applications. This is a VERY THICK WIRE, which is needed for the amount of current (20 Amps) indicated by the 20 Amp fuse and it matches with the 2.5mm wire specification in the Stebel drawing. All the same caveats given above regarding vehicle damage apply to using the wrong size or type of wire.
- Connect another 10 AWG wire from pin "87" of the relay to the POSITIVE (+) terminal on the horn. The same warnings listed above apply.
- Connect another 10 AWG wire, preferably of a different color from those used above to aid with identification, from the horn's ground (-) terminal to a metal chassis or support surface. Same warnings as above for wire size. Do not connect this wire directly to the battery negative terminal, as this will bypass the charge regulation circuit and can result in charging problems.
- Double check all your connections, tracing from end-to-end, to make sure everything is hooked-up properly and the wires are safe from sharp edges and hot, moving or vibrating parts. Also make sure you haven't broken or cut the insulation on any wires.
- Reconnect your battery but not the wire to the horn relay but be prepared to quickly disconnect again. Check for any heating of the OEM horn wires or, worse, smoke. If you feel the wire becoming hot, quickly disconnect the battery and check for any breaks in the insulation or wrong connections. Wait a few minutes to be sure.
- Turn on the ignition but don't start the engine, and check again. Press the horn button for 30 seconds and check again. (Obviously, the horn will not make any sound at this point.)
- Turn off the ignition.
- Check that the fuse is installed in the hot wire from your battery to the horn relay.
- Connect the hot wire to your battery. Check the wire and relay for any overheating or smoke. Wait a few minutes to be sure.
- Turn on the ignition but don't start the car, and check again for overheating wires.
- Press the horn button. Your horn should now work.
If the horn still doesn't work, and everything is wired correctly, you may have a blown fuse, a bad relay or a bad horn.
- Check the fuse first to see if the fusible link is melted or broken, as this might have occurred during your initial installation attempts.
- Then try testing the horn directly to the battery by taking the hot wire off the relay and touching it to the positive terminal of the horn. The horn should sound.
- If the above are OK, then process of elimination dictates that the relay is bad.