If I understand how your system works, you have to have a compressed air source to power it. Is that car mounted or motorhome mounted?
Sounds like a slow leak in the system somewhere. You are going to have to use some of that bubble solution on the fittings.
If the compressor has to be mounted in your toad and powered from the toad battery for your breakaway switch to work properly. You can add a charge line from your motorhome to your toad to keep your battery happy. ToadCharge is at least one commercial solution and the kit contains all of the wire, connectors, circuit breakers, and voltage regulators that you need to keep everything happy.
Roger & Mary
2014 Tiffin Phaeton 36GH
2012 Honda Fit toad