Since we’ve added the ARB Lockers to the jeepfan.com 2004 TJ Unlimited it’s time to actually get the lockers operational by installing an ARB Air Compressor along with its air lines.
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There are several compressor options but a simple, reliable and inexpensive option is installing ARB CKMA12 compressor. It’s small and can be installed under the hood in a good location. We settled on the top of the driver side fender on our TJ.
Compressor Prep
Once you settle on a location it’s best to prep the compressor before installation, follow the directions. This ARB model has some flexibility and the small air reserve can be rotated to find an optimum position. We found our best position and tightened the reserve down to ensure its position. Next we installed the air pressure switch followed by the front and rear locker solenoids.
air pressure switch 
air reserve plug 
rotate for easier install 
locker solenoids 
solenoid installation 
solenoids installed
With the compressor prepped we did some final positioning and drilled holes for the compressor mounting bracket. The bracket was installed using some rubber bushings on the top and bottom of the fender to help with vibration. Use locking nuts to prevent the bolts from coming loose. The compressor was mounted to the bracket.
holes marked 
drilling the fender 
bracket mounted 
installing the compressor 
completed install
With the compressor installed we moved on to plumbing the air hoses that will lead to the axles. Since we have front and rear lockers one line will go forward and the other to the rear. It’s essential to place the lines where they will not be exposed to heat, moving parts or debris. Depending on your situation some Jeepers place the line within flexible plastic wire wrap or even steel brake line.
Lines plumbed to the compressor 
Rear line leaving the engine compartment 
Rear line along the frame 
Finally attached to the axle 
Rear line attached to the rear brake line
Be sure to leave enough line at the axle to allow movement of the axle without the line pulling tight. Attach the line to the connector and install the spring guard that will protect the end. After the compressor wiring is completed test the locker operation and check for air leaks.
Next: Air Locker Wiring
