air bags and controllers

I can't comment directly on the use of airbags, but I can tell you that almost since day 1, I've run an on-board air setup on my truck, with a compressor (an ExtremeAire unit) mounted with rubber isolators on the transfer case skid plate, just behind the T-case itself, and a 2-gal. air tank mounted on the driver's side frame rail, just ahead of the fuel tank. I use a quick-connect coupler (female on the compressor, male on the line) to connect the supply line from the compressor to the tank, with a check valve on the tank inlet. The QC leaks just enough that it acts as a relief valve for the compressor (that way, the compressor's not starting up against a load), and since the check valve is there, no air leaks from the tank. From the tank, I run air lines both forward and backward along the inside of the driver's frame rail, zip-tied to the fuel line on the front, and brake line towards the back. It's tempting to try and route the lines inside the frame rail itself, but unless you horizontally elongate a hole somewhere, it's too sharp of an angle to come out of the rail, and still lay flat. As long as the lines are tied up well, there should be no problem.

For wiring, I come off the driver's side battery to a 100A circuit breaker, feeding a 100A relay, that feeds the compressor. The relay is switched via the ignition circuit, and runs through a dash-mounted switch (so it can be turned off), then through the tank-mounted pressure switch. I got all my parts for this at