When you say right side gauge, I take it as you have dual gauges. It looks like they've changed the kit some since I last played with them. But the brief synopsis is there is a sensor in the suspension that tells the compressor to fire up and level out the truck. The picture I see does show the compressor button in the gauge panel, so I would start by trying that to see if the compressor fires up, or press the purge button and see if you can dump air and start the compressor.

A leak would show the pressure as low and the compressor will always try and compensate for the loss. Since you don't think the compressor is running, I doubt a leak would leave you with 5psi. You might want to crawl under the truck, find the level switch and try pressing it in to see if it's functioning.