Hi Folks, doing some research before I dive into my very first install. Looking to install a set of Nathan P3s on my 2004 Dodge Ram 1500, reg. cab, short bed and need some advise / opinions. I have the P3s already and will be purchasing the 540 Air Set Up from Hornblasters as soon as I build up fundage. I plan on a stealth install with tank and compressor on frame rail and the chimes racked where the spare is now. I want this fully independent of my stock horn and plan on putting a push button where my cig lighter is now. I see a lot of installs utilizing a toggle to turn on the compressor when needed. Can I forgo the toggle and just have the compressor active and ready all the time with run time determined by the pressure switch when the tank needs air? Is there an advantage / disadvantage to having toggled air versus non-toggled? If the lines and fittings are all sealed and leak free, I am thinking that the only time the compressor would run would be when air is needed to the tank. If this be the case, what would the need be to turn the system off manually? Also on the horn button, has anyone here utilized the cig lighter as a camouflaged button location? If so, how difficult was it and what type of button did you use to replace the lighter? I would love to have a button that looked just like the cig lighter, so nothing can be seen out of the ordinary in the cab. Has anyone disguised their horn button as the cig lighter? I will post pics when I have the whole system up and running. Thanks in advance for the advise.
For your Air Compressor I would Recommend a Toggle switch incase later down the road you get a leak or if you want to drain the tank and still be able to drive your truck. I have not regretted having toggled air! I had a small leak in my air system and about every 45 minutes my air compressors would Kick on and well lets just say if you are driving with out control of your air compressors it gets pretty annoying (of course if that happens you can crawl under your truck and unplug the air compressor from the pressure switch but I like doing it the easy way by just turning off a switch 
) . As For the horn button Idea, Pretty great Idea! I also have my horns on a separate switch as well due to a bad connection in my steering wheel horn pad having a bad connection. I wish you good luck with your install! I hoped I helped out with your air compressor Idea.
Firstly, here is a pull push switch that is similar looking to a cig lighter. I would not imagine it being to hard to butcher the top off a cig lighter and replace the one on the switch or just use the switch.
Toggling the compressors? I have in the past had various switches on one install. You get pulled over at side of the road, you dont need the compressors pumping away whilst your convincing the nice law enforcement officer that you dont have horns etc etc.
I put switches on everything!! I had a faulty relay which got stuck on it meant the compressor pumped my 8.5g tank up to 300psi whilst my truck was parked up and only stopped pumping because the battery went flat.
I would get into the truck and switch on one main switch that took power from the battery to the twin compessors.
I also had a switch that powered the relays, electronic pressure gauge etc & finally I had a switch to switch between stock horn & Train horn.
Yeah you’ll need a switch to kill the compressor, not only for the times when you don’t need it running (like when the police pull you over) but also so it doesn’t drain your battery when the engine is off.
Here’s a couple pics from my install that might help you:
If you have a Ram truck with the power adjustable pedals, then you know this is where it sits on the panel above the emergency brake release. If you don’t the power pedals, this spot is unused and you can make it look totally stock by installing a Radio Shack switch here, as I’ve done.
Tank and compressor mounted to the passenger side frame rail.
If you have questions, just ask or send a PM.
-Kris
Thank you for the responses and a wake up call to something I had not considered. Would not be good to have the compressor humming away while I deny any knowledge or ownership of said compressor. Toggled it is. This is why this forum is great!!
Have fun with them, and post some pics too!
-Kris
Mine is toggled but also connected to a power line that is switched with the ignition. That way I can leave the comps switched on, but if I turn off and exit my truck the comps don’t continue to run. A few reasons for that… I don’t want my comps running when the truck is off and having them drain my battery, I don’t want to have to toggle them off every time I exit, and when I park it I don’t want to hear the comps running in the parking lot, gas station, or driveway as I walk off.
Yes definately have it toggled.
Hot air/cold air can make your PSI rise/fall.
If you are already close to activating your pressure switch and you park your car for the night, then it can activate itself when the temp falls. If you live in an area where temps fluctuate alot.
I know this cause it happens to me all the time. I will check the PSI during a warm day and in the morning and its fluctuates by at least 10psi.
just use a switched ignition source to power the realy. that way it only runs when the vehicle is on
Definitely have it on a toggle switch as a KILL switch, not an activate switch. Run a switched ignition supply wire to the toggle, then to the pressure switch, then to the compressor relay. This configuration (with the toggle left normally on) means your compressor only runs when the key is on/truck running and you won’t forget to activate it and be left without air when you want it, but can be shut off when you don’t want the power draw or noise.