For about 4 years I’ve had two sets of (ebay) kleinn 4-trumpet “train horns” which are more like the little horns they put on semis, two 1 gallon tanks, and a DC2000 compressor on my 02 Denali (hooked to the stock steering wheel horn button with a kill switch in case I wanted to deactivate the loud horns and just use the stock one). I had a lot of fun with this and it was actually fairly loud and could blow for 4-5 seconds. Recently I’ve had some air leaks and difficulty building/holding pressure issues that caused me to want to redo the entire setup to be bigger, louder and more reliable.
To that end, I purchased a K3LA set off ebay for $430 shipped. I would have bought a P3 (my favorite sounding horn based on video clips) or a K5 but both were far too big for the space constraints in my truck. The K3 I got is a new casting and looks to be basically brand new, all shiny parts and hardware with no old paint, scratches, etc. Might not have even been installed as the threads for the air line were clean. The plates/diaphragms inside looked literally brand new with barely a mark on them and no dirt whatsoever, the rubber was still brightly colored and soft/pliable. I think I got a great deal considering that a new K3 goes for almost a grand from hornblasters.
Then I bought a twin set of chrome viair 400c compressors for 300 shipped. I got a tinted backlit air pressure gauge from glowshift for 35 bucks shipped, and had to add an airline/fitting kit from summit/autometer for $10 more. I ordered the rest of my stuff from hornblasters, including one 5 and one 8.5 gallon tank, 1/2" airline, and a GW replica manual valve. That stuff was another $275. Then I had about $50 worth of fittings and such for the install (each fitting is $3-6) and $25 worth of metal for making brackets, plus a few drill bits.
This week I set to installing it all, which took about 3 days working 4-6 hours a day on it at a light pace. The goal is to have minimal intrusion on the appearance and function of the truck with this install…the only thing I had to remove to make this happen was the spare tire. Also unless I showed the average person where the horns and tanks are, they wouldn’t notice. I didn’t want stuff sticking out/up/whatever to be readily visible to the average person.
First I disassembled the horns and powdercoated them (I have a small setup in my garage to do all my own powdercoating). The longest horn was quite a challenge as due to the small size of my oven there was no good way to hang it without leaving at least one or two marks in the coating. I did flat black and gloss red, which matches the powdercoat on my engine/accessories in my truck. I used a dremel tool to sand the raised letters back to bare metal.
I also did the manual valve handle and top half of the body which were gray and brass.
I spent about half a day fabricating this custom mount for the manual valve. It fits the contour of my floor pan/trans tunnel and bolts to the front rail of my seat. It tucks the valve in tightly between my seat and center console and is very sturdy…pulling on the valve fully open, the mount only allows 1/4" or so of movement total. When you look in the truck, all you see is the valve handle itself.
I mounted the tanks back where the spare tire used to go. Installed on the tanks are the two air compressor leads/checkvalves, one air fitting for onboard air/airline, 175psi safety valve, 110/145 pressure switch, the air line to the air gauge, the air line connecting the two tanks, and the air line for the horn/valve.
I mounted the twin compressors just in front of my rear bumper under the truck. I had to make a couple of brackets from steel bar and weld onto the frame to give me something to bolt the compressors to. Each has it’s own 40A relay which is fed by the 4 gauge power wire that runs my stereo system and a stinger 150A circuit breaker at the battery. I ran two 10 gauge power wires to the two compressor relays from the 4 gauge wire (since it was too big to connect to the relays, haha). I also hooked up a compressor kill switch inline with the pressure switch which controls the relays (via ground) so that if they are too noisy at some time (when I’m hauling people in the back, or in a parking lot etc.) I can turn them off even if the pressure switch is trying to run them.
My truck also has rear air shocks to assist in load leveling when loaded/hauling, which are operated by a seperate compressor and controlled by the truck’s BCM automatically. I’d like to have direct control over lift/lowering so in the future I plan to tap into one of the remaining air ports on my tanks and use a fill valve and a dump valve along with a DPST momentary switch to let me raise and lower the rear of the truck as needed.
Finally it was time to mount the horns. I located a spot on the frame rails in the engine bay where I could mount my crossmember, which will hold the horns. I made the crossmember from a 3’ piece of steel angle. I welded two bolts to the tops of my frame rails to bolt the crossmember to, then bolted the horns upside down to the crossmember (air inlet/mounting flange facing up, only way they would fit).
