Last night I finished a few train horns for trucks. These train horns for trucks were based upon the Nathan AirChime design. I bought the blueprints off the Internet and wielded the horns just like the real train horns. I bought a used compressor from Viair off Ebay and went to Home Depot to buy the fittings. Installation was a breeze because I have a background in car mechanics. My initial problem was an air leak between the valve and compressor. I fixed the leak with some super glue, and double checked all my fittings. I tested the horns and they blew around 145 dBa, which is really loud. When you buy a train horn, you have the option of installing it yourself or paying a professional to perform the job. Train horns for trucks are pretty difficult device to install on your truck, but here are some instructions. You will need to first measure the surrounding area on your truck to make sure the actual train horn can be mounted. After that, you need to mount the compressor and air tank in a safe, cool location. Avoid any area that gets hot because the contents are under pressure it may explode with too much heat. Then connect all the fittings and make sure there are no leaks.