Dodge RamCharger Central banner
1 - 1 of 1 Posts

· Administrator
29,558 Posts
Discussion Starter · #1 ·
On-Board Air System on a Dodge Magnum V6 / V8
Submitted By: tv_larsen Date: October 4, 2015, 05:49:08 pm Views: 5147
Summary: This How-To covers the install of an engine driven on-board air system using a York A/C compressor and Jungle's Magnum engine compressor brackets.
Having a compressed air source on your vehicle is very useful. It adds more utility to any car or truck. With on-board air (OBA) you can inflate your tires, operate an air locker like an ARB, or power that set of train horns. You can also run pneumatic tools like impact wrenches, grinders, drills or body saws.

OBA systems like this use an A/C compressor driven by the engine fan belt. Some compressors work better than others. The RV2 compressor used on most Mopars in the 1960's and 1970's works very well, but it is large and it can difficult to mount to your engine if factory brackets aren't available. The most popular compressor used for OBA systems is a York compressor. Yorks were common on several brands of cars, but was mostly used in Fords and Volvos.

York compressor mounted on Jungle's HD compressor bracket
Note: To work with the Jungle bracket the York compressor must have a v-belt groove located at 2.25" as shown in this Kilby photo. Not all compressor pulleys are the same.


For more information on the York compressor and OBA systems visit:

I installed this system on a 2001 Dodge Dakota with a 3.9L Magnum V6. The process is very similar on a Magnum V8 and/or in a full-size truck. My Dakota install required removing the stock air box and the fit between the inner fender and the hood was very tight, but it did fit with clearance. I also notched one bracket for A/C hose clearance and added a hook to keep the other A/C hose from contacting the compressor pulley.

Note: This install uses a prototype Jungle compressor bracket so it might vary slightly from what he sells. I modified my brackets slightly because the Dakota factory A/C lines were so close to the York compressor.

Kilby provides this wonderful diagram of the entire OBA system. My system only differs from this in some of the plumbing and wiring.

Part sources - this is where I got my parts:
Install the Jungle compressor alternator bracket and the Kilby combo pulley.
  • Disconnect the battery.
  • Loosen the serpentine fan belt and remove it from the alternator.
  • Remove the 2 bolts that mount the alternator.
  • Using an impact wrench remove the alternator pulley nut, remove the stock alternator pulley and install the new combo pulley and re-install the pulley nut with the impact wrench. The stock clutch fan blades were only about 0.1" from the new pulley and would contact it at high RPM, but slightly bending the edge of the blades solved that.
    I used the overdrive pulley to increase the alternator and compressor outputs at low engine speeds.
  • Mount the alternator back into the original position, place the new compressor bracket over the alternator as shown and use the new longer bolts. Don't forget to re-attach the ground wire on the lower bolt.

Install the York compressor:
  • Attach the Jungle compressor bracket to the compressor with the 4 new bolts as shown.
  • Add 8 ounces of oil to the compressor (this is the easiest time to add oil). You can use 10W30 or ATF, I used the A/C ester oil that was included with my rebuilt compressor.
  • Attach the compressor bracket to the alternator mounted bracket as shown. Make sure you use spacer between the two plates on the lower moving adjustment bolt.
  • Install the V-belt and tension it by rotating the compressor up then tightening the bolts. Caution, it is easy to over tighten the belt, slight tension is all that is needed.
    Note, because of my Dakota's very tight engine compartment I had to use the shortest belt length possible. This belt length required the serpentine belt to be loosened so that the alternator pulley could be rotated by hand to "roll" the new v-belt onto the combo pulley. If you have more clearance above the compressor you may try a slightly longer v-belt.
  • Install the Kilby custom pipe-thread adapter fittings.
  • Install the 1/2" Solberg FS-06-050 air intake filter to the suction side port - the head of the compressor is marked to indicate which side is "suction" and which is "discharge".
  • Assemble the manifold with the pressure switch (90/120 psi), 3/8" moisture trap and 3/8" check valve. I also installed a air hose quick coupler in the manifold.
  • Mount this assembly in an appropriate position near the compressor.
  • Attach the Viar 3/8" x 24" leader hose (P/N 9792) from the discharge port of the compressor to the check valve. The leader hose has a swivel fitting at one end to make this assembly easy.
  • Mount the air tank in a safe location - I mounted mine in the truck bed.
  • Run a 3/8" air hose from the output of the manifold to the tank. Route the hose away from heat, sharp edges, and moving parts.
  • In the tank install the pressure relief valve (175 psi). This will protect the system from over pressurization in case the compressor fails to shut off

  • Install a 1/4" petcock valve in the bottom of the tank so that you can drain any moisture that will accumulate.
  • I also ran another hose from the air tank to a hose quick coupler located at the rear of the of the truck bed for convenient air access and a 1/4" hose barb for a hose to a in-dash air pressure gauge.

  • 618855

    Run a 1/4" air hose from the tank mounted hose barb to the dash mounted air pressure gauge.
  • From a fused and switched power source, run a positive wire to a switch located in a convenient location, then to a 30 amp relay under the hood near the compressor.
  • The relay can draw power directly from the battery, then route it through the pressure switch to the A/C compressor clutch.

    This wiring keeps the high amp clutch load from running through the firewall, and uses a low amp switched source so that the compressor clutch can't run the battery down when the key is off.

    The pressure switch complete the power circuit to the compressor clutch until the pressure reaches 120 psi, then the switch opens breaking the clutch power circuit until the pressure drops below 90 psi where it closes again allowing the compressor clutch to re-engage and fill the tank back up to 120 psi.

    I used a universal relay/fuse box from Ebay seller "bodoke0326" to give me 5 relay switched and fused power circuits for OBA and other accessories. This really helps keep the wiring neater.
This system provides air that you can use anytime and anywhere. I had OBA on my previous off-road rig and found it to be very useful. With it I aired up my tires, other people's tires, seated the bead on a tire, actuated an ARB air locker, and used it to power a pneumatic body saw to remove some sheet metal in a grocery store parking lot 300 miles from home. This York powered OBA system should prove equally useful.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.