Viair 420C Compressor Install: Part 2

After mounting the compressor, all that was left was to route the power lines to the switch and run the air line through the wall of the second battery compartment. Easier said than done! The compartment is shared by a number of other components, some of which get quite hot, so I had to make sure the wires and steel-braided leader hose wouldn't come into contact with anything that could damage them.

I decided to mount the switch in front of the ABS system as it didn't require much depth inside the box and a swiveling quick-connector was mounted beside it. Both mounting positions required a 1/2" hole in the wall of the battery box. The switch I chose is a 50 amp SPST toggle switch and is rated high enough that I didn't have to wire a relay into the system. The quick-connector was threaded through the wall of the battery box and screwed directly into the 3/8" to 1/4" reducer on the end of the compressor's leader hose. Teflon tape was used on all of the threaded connections to ensure a good seal.

The leader hose is temporarily zip-tied to the inboard wall of the battery box to keep it from resting against anything. I purchased some insulated hose clamps and nylon push-in connectors and will be re-routing the hose and securing it later.

The last step was to mount a dust cap for the air connector, attach the wires to the switch with round terminal connectors and install the fuse in the inline fuse holder. Once the connections were all in place, I tested the unit and checked for leaks - everything works perfectly!

I also tested it with the battery cover intstalled and there is more than enough space for it to draw air as well as stay cool. The unit is relatively quiet (especially with the cover in place) and there is virtually no detectable vibration in the engine bay.

This project is not very difficult, it just takes some good planning and selecting the right components. Overall time spent was about 5 hours, but a more experienced person could do it in less. Good luck!