Anyone here upgrade their horn? I'm interested in doing so, but since most loud horns require a relay that connects to the battery, I'm thinking it will be more complicated than I'm prepared to deal with since the battery is in the trunk. I'm interested to see how difficult this would be.

 

No problem. Remove the wire going to your existing horn at the horn. Make a new wire that extends from that plugin on the wiring harness to your new relay and use that signal to trigger the relay. Do not cut the exisiting harness. By doing it this way, you can remove the new horn, relay and wire extension and plug the existing wire back to the original horn (that you left in place) when you decide to sell the car or go back to the original horn.

 

Connecting the new horn to the relay is no problem. But the relay also needs to connect to the 12V battery. Therein lies the issue.

 

I did this after the low side went out on my factory horn. The horn gets a good workout here dodging all manner of inattentive stupidity. New one has a small air compressor piped into a real horn. But this system with my existing hi side factory horn wired in parallel was more than the 10 amp fuse could take. The wires were all 18 gauge, plenty able to sustain short bursts of moderate amp draw, so I stuffed a 20 amp fuse in the holder and away I went. No problems at all using the existing horn relay and wiring.

 

Good to know that the horn switch can handle more than 10amp. Which horn did you end up going with? I'm considering the Wolo Bad Boy, but it seems to have man quality control issues. Also considering the Stegel Nautilous. Even though this horn tends to be marketed toward motorcycles, it is 139Db and I've seen some youtube vids demoing it in their automobile.

 

I got the Wolo Bad Boy, $40. Not quite as loud as I thought it should be, but a definite improvement over OEM.

My favorite part is coming along side some dipstick drifting into my lane because they are head down, steering with a knee and texting with both hands, One mighty blast from their blind spot and hilarity ensues.

The inspiration of course was my buddy the crazy Russian mechanic who somehow got a hold of a locomotive horn on eBay for $1,300 and made it work under the hood of his Navigator. Compared to that, the Wolo falls a bit short. No quality issues I could see.

 

I have genuine air horns, aka train horns, on my pickup truck. They make roughly 150 decibels, and hurt the ears if you toot them with the windows open. But the horns, with the air tank and compressor, are rather bulky. Plenty of room under a pickup truck, but way too large for a TCH.

I looked at the TCH shortly after I got it. There seems to be a little extra air space behind the front bumper and grille. That might be enough to hold the horns themselves. But, the compressor and tank just don't fit. (I want to be able to carry a suitcase or two in the trunk, and a couple of passengers in the rear seat. If you are willing to use either of those spaces, the compressor and tank would fit.)

 

No need to go back to the battery. Pick up a tap in the underhood fuse box. If a fused link of 20 amps or so is not large enough, add a line from the underhood battery connection point in the fuse box and add your own fuse link.