Finally got my air horns installed!

[mach92bill]

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View attachment 75753View attachment 75748We. . , after about two years of procrastinating, I finally got around to installing my air horns. The biggest reason I can quote, is that I was trying to find the easy way to install all the components with a minimum of work and tearing hide off of my hands. . I have aftermarket running boards installed and they have a fairly hefty mounting bracket just below the front door edge underneath the cab, held there with one existing bolt. I acquired a 6 inch by 10 inch bt 1/4 inch thick steel, drilled it to attach to that bolt, then drilled two more holes in the plate and bracket to attach the piece of iron, which extends rearward from the running board bracket. I then attached the tank to this 1/4" plate. The compressor is mounted just behind and slightly above the right side of the bumper. Had to use some spacers and only three bolts, but worked our OK. I made an angle bracket and drilled to fit the bumper attach bolt, then attached the horns to this. Plumbing and electrical finished up the job. Power is supplied to the compressor directly from the battery, but I installed a relay to switch the power on and off when the key is turned on. I also added a switch in series with the relay contacts, so that I can manually disable the compressor circuit when its cold enough for the grid heater to be working. I'll try my first attempt at attaching some photos.

 

[Crunch]

Nice install, but do you worry that the gauge pointing down like that will get hit by rock and other road debris? I've got tiny dings and chipped paint all over the bottom of my truck from country roads kicking up gravel.



And remember--if you can sneak up on someone, let loose on the horn and they soil their drawers it's worth a thousand points... :-laf

 

[Allnew2Me]

Nice compact install. Although you certainly don't want to break a gauge, I think I would be more concerned about the wiring catching on brush. You may want to get some plastic loom and wrap them up out of the way.

It appears that we have the same horns, are those Grovers? At what pressure are you running them? 75psi seems to work well, anything above that doesn't seem make them any louder on my set.

 

[jelag]

All my trucks have pac-brakes, air bags, and air horns on them... . here's what we've learned over the years...

What we've learned from installing PacBrakes that go on trucks in cold weather is that any moisture in the system will freeze in the winter and break apart the mechanical switches that regulate pressure and can damage the head of the compressor... Keeping them in the engine compartment so they can warm up and work that water vapor out of them is a must.....

After many trips to Edmonton in the winter I can also share that if you find some shrink tubing with an adhesive in it... and use a un-insulated butt connector on all your connections instead of ones you've used... you'll get more than one winter before you have problems with the connections... .

 

[mach92bill]

Guage is only there temporarily to adjust the pressure switch. Just happened to have it handy. I set the pressure to approx 110 PSI, but will play with it some more to find optimum pressure. The lines and wiring hanging down is before I tidied up the job. Jim,thanks for the tips. Did you mean the brass fittings rather than the push-in type?

 

[mach92bill]

Jim, after reading your post again, I now see you are speaking of electrical connections. If you are heading to Edmonton, send me a PM. I live very close to the scale north of Calgary on Hwy. 2.

 

[Crunch]

75psi seems to work well, anything above that doesn't seem make them any louder on my set.

The smallest diameter tube in the system determines that. It's the same reason you can't keep increasing the pressure on a garden hose to match the city water pressure on your 3/4" reduced line, or get significantly more flow with a bigger exhaust and tail pipe coming off your 3" header.

 

[CharlesHoward]

Nice and neat install!

Mine looks a lot messier!

I got a 5 gallon tank which fits up under the passenger side of the bed.

Compressor, Switch, etc are under the rear seat just under the cab.

I can't get the cheap relays from auto part stores from the ignition source to stay working (they're exposed, albeit under the cab near the pressure switch).

I also had to drill a hole in the pressure switch cover to drain water.

 

[mach92bill]

Try an industrial electronics place for a good quality relay.

 

[Allnew2Me]

The smallest diameter tube in the system determines that.



Pressure and flow are two different things. I get 75 psi at my interior gauge with only a 1/16" line feeding it. Boost gauges are the same line I believe and they can show 70 psi easily.

The smallest diameter will certainly limit flow, but not the static pressure and that is what I was refering to, I set my regulator at 75 psi static pressure. When I hit the horn the gauge shows a quick drop and then stabilizes at close to 75 psi. With a bigger air load I would guess that the pressure would drop more with small lines.

 

[Crunch]

Pressure and flow are two different things. I get 75 psi at my interior gauge with only a 1/16" line feeding it. Boost gauges are the same line I believe and they can show 70 psi easily.

The smallest diameter will certainly limit flow, but not the static pressure and that is what I was refering to, I set my regulator at 75 psi static pressure. When I hit the horn the gauge shows a quick drop and then stabilizes at close to 75 psi. With a bigger air load I would guess that the pressure would drop more with small lines.

I was thinking in terms of Bernoulli's principle. It deals with fluids, so it may be different with a gas. But in the back of my head I tend toward believing you can only cram so much stuff--gas, liquid or solid through a hole at any given time.