Introduction: HOW TO INSTALL ONBOARD AIR COMPRESSOR IN CAR | WIRING+MOUNTING VIAIR 444C SOURCE KIT SYSTEM IN DODGE RAM
Hi there guys its Geramicc85.
Today I will be working on my on board air system project on my dodge ram 1500. It's about time to install the compressor. I got this VIAIR air compressor 444c model. It runs on 12 volts and draws up to 38 amps with an maximum operating pressure of 200 PSI. This things maximum air flow is at 3,5 cubic feet per minute. And it seems to be built very solid and weighs 20 pounds.
The unit has two brackets with four rubber buffered holes on it for an easy bolt on installation. It came with a pressure switch thats going to turn the unit off at 200psi and turn it on as soon as the pressure in the tank drops under 165psi. Also there is this relay to connect the compressor to the power supply. And then we have the air filter unit to keep dirt and dust from going inside the unit, it comes with two spare filters. The filter can be screwed directly on to the compressor or you can use a hose to remotely put the filter somewhere clean and dry. These are the small bolts that are included to mount the compressor.
I ordered some extra parts for the connections. There is this 1/4 inch T which i want to put directly behind the check valve here so that the pressure switch can be mounted close to the compressor. You could also put it on the tank but this way I don't have to run so many wires. Then I got these screw-in quick connectors for all line connections. These are just screwed in and then you just slide in the polyamide line on the blue side. This air lines outer diameter is 8mm and the inner is 6mm. According to the manufacturer it can be used for working pressures up to 275 psi. I will be using this Teflon tape to seal all pneumatic fittings to avoid air leaks. A good thing is that you can easily add outlets to the line by putting in one of these Tees for air horns or whatever.
Now the power wires on the compressor are not that long so if you wanna put this thing somewhere else then next to your battery you have to get extra wires. But before that I want to find a good spot for mounting the compressor. I dont want to put it in the truck bed since it will be in the way and putting it underneath the truck would expose it to dirt and moisture. Therefore, I decided to install the unit somewhere in the engine compartment. I have this cold air intake here in the front, behind that there is the control unit and the evaporator of the propane system. Here above the units would be enough space to bolt it to the fender. But because I want to avoid drilling into the metal of the vehicle, I think that this would be a very good spot. The air filter box is made of metal and pretty stable. The compressor would sit pretty high right under the hood which helps to keep dirt and moisture away from it. And also the install will be easier here through good accessibility from both sides. Ok this is where its gonna be so i start to bolt on the compressor. I remove this existing screw and use the hole to attach the compressor. Then the other 3 holes can be marked for drilling. That way I make sure the holes match later. The drill i am using is just a lil thicker than the screws so that they dont have play in the hole later. So I mark where to drill and then take out the one screw again so that i have place to drill. Ok the three holes are drilled and now i trimm the edges with a large 10mm drill. I make sure that no metal chips or dust remains in the engine compartment to avoid rust. Now the compressor with all four screws can be mounted. Alright the compressor now sits nice and tight on the back of the air intake box.
Now I'll take care of the air line connection to the air tank, which is located on the passenger side on the underbody. I did a video about the air tank install, you will find a link to that at the end of this video. The Viair unit comes with a check valve already installed. It prevents the air from pushing back into the compressor when the tank is filled up. Now i screw that T-piece on there with Teflon tape. On the other end of the Tee I put in a 1/4 quick connector. The pressure switch is now put in the middle. wrapping it nicely with Teflon tape to avoid annoying leaks. I screw it in and tighten it up a little.
Now i am running the line to the tank by sliding it on the fender all the way under truck. The air tank has 3/8 inch threaded connections. I screw in one of these angle connectors and tighten it. Now the line can just be plugged in. Now I can cut the line to the right length using these pruning shears since I don't have professional air hose cutters. Not pinching the line too bad while cutting helps to avoid leaks at the round plug-in connections.
It's time to screw the air filter onto the compressor. To open the housing you can use a small screwdriver if you need to change the filter. I remove the little nipple here and screw the filter on. Make sure the filter housing sits on nicely and don't over tighten it since it has plastic threads.
Its time to take care of the power supply. For that I first put a 5mm thick red wire from the battery to the compressor. I am running it together with a small dual wire over to the other side and secure it with zip ties. The wires disappear nicely behind this weather strip. I am adding a fuse to the positive wire and then prepare the end for clamping it to the battery later.
Now i go over and connect the black negative wire coming from the compressor to the frame of the truck. For that I just use an existing little bolt there next to the Propane ECU.
I go on and take the end of the wire i just ran to the battery and solder it to the relay pin 30. You see a diagram of the used relay in the corner of the screen. OK then i solder the red wire thats attached to the compressor on to the pin 87.
Only wires that are missing now are the ones that help to switch the relay. Well i solder the thin dual wire that I ran behind the weather strip to pins 85 and 86. polarity doesnt matter so far. Now i run this dual wire to the pressure switch and cut open one of the wires and connect both ends to the pins of the pressure switch. Having it soldered on, the dual wire is now beeing ran all the way under the dashboard. Here I got this little switch that can control the compressor later. The switch again is connected the way that it only gets power with the car ignition on. The way it works in the end is that car ignition and dash switch as well as the pressure switch all need to close the circuit in order to work the relay which turns the compressor on.
So now i connect the prepared power cable to the battery. Then i use zip ties to secure all air hoses and power lines. That way nothing is hanging around in the engine compartment and it looks a little nicer too.
I can finally run the compressor for the first time. Seems like it's working as it should.
I hope this video helps you in any way. Feel free to check out more of my air parts install videos on the underbody air tank and the truck bed air outlet port. I really appreciate every thumb up, every subscriber and every comment. Thanks a lot for watching and good luck with your project. Until next time this is Geramicc85 signing out!
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