AIR HORN

By jprtroy

Wanted one of these for some time! The tiny electric, stock “beep beep” horn that came with my new Dodge Cummings Turbo diesel just doesn’t do it! I found the horn at a local truck dismantler. They have new horns in stock but I didn’t want to spend the coin for a new one, so I bought a used horn. The horn is a Grover 1700.

Locating a spot to mount the horn; the measurement of the trumpet is 24” long, and 6” wide at the business end. I was hoping that I could fit the horn behind the front bumper, but it appears to be just a little to big to fit. There’s certainly no room under the hood for it. Thought about putting it up under the cab, facing forward, but that just didn’t feel right. I finally decided on a spot up front. The frame cross member is flat; there’s enough space to actually install the trumpet on a flat surface. The business end of the trumpet will be aimed towards the steering box. Just a little bit of the horn is visible hanging down from the below the air dam.

I choose this spot, because it’s easy to get to, and it’s at the front of the truck. Is it the best place for the horn? For my use, yes. If you wheel your truck, you may crunch it at some point from wheeling by locating it there. I don’t wheel my truck so the chances of me crunching it where I’m putting it are slim.

The frame was drilled to accept 1/4x20x2.5” bolts.

On the cross member, there is an oblong hole (located on passenger side) that the air connection fits up in. (Also used this hole to install the bolts used to hold the horn)

Plumbing the horn was not hard, once I decided on the kind of tubing I was going to use. I have a lot of SS 3/8” tubing I could have used, but when I laid back on my creeper and scooted under the truck to look for suitable places to run the SS tubing easily, I was dismayed at how much work would be entailed to do this. (Like dismantling the front end! Which I wasn’t into doing) I choose the more flexible route. The 3/8” flexible tygon tubing I had for extending the breathing vents for the entire drive train worked right nicely for my air horn. I started at the tank’s manifold. Installed my new 12vdc air solenoid into one of the available ports.

I started with a 24vdc air solenoid, it operated on 12vcd just fine, with 0 PSI in the tank! With 140psi the 24vdc solenoid wouldn’t operate on 12vdc, until the pressure in the tank dropped below 40psi. This wasn’t gonna do! That’s when I purchased and installed the 12vdc solenoid. I connected the flex tubing to the solenoid (The solenoid has an inlet and an outlet! Please be sure to orient it properly) then began the task of running it to the front of the truck along side the driver’s frame rail. I crossed over the frame at the skid plate, then, secured the flex tubing to the already present crank case breather extension tubing I installed shortly after getting the truck. The crankcase breather tubing extends all the way up to the front of the motor, so I strung the flex tubing along side it, and secured it with cable ties every foot or so.

Up at the front I had to cross the gap from the front of the motor to the frame cross member. I did, and left some slack (for articulation) then found a wiring harness loom and secured the flex tubing to it, and ran it to the horn’s connection point.

What’s left is to terminate the air solenoid’s wires and connect the hot lead to the trucks horn relay. I choose to ground one of the solenoids lead to a bolt used to hold the air tank to the bed, the other (hot lead) is connected via male & female spades to the horn relay. Nothing fancy about the connection, I simply located the proper relay, removed it, stripped the wire back enough to allow me to insert it into the relay’s receptacle, then reinserted the relay.

Eventually will operate the air horn from a switch located on a shifter knob. But for now, the stock horn relay will do.