As the RRC EAS is what i'm familiar with, weirdly..
Try unpluging the ECU controlling the suspension On the amp plug you'll find if you pull back the sleeve all the wires are numbered loop pins 1 & 8 to run the compressor for a couple of minutes to charge the system.
3. Then to raise each corner connect the following together with a loop of wire:
3.1 left rear pins 26, 11, 8 & 1
3.2 left front pins 26, 10, 8 & 1
3.3 right rear pins 26, 28, 8 & 1
3.4 right front pins 26, 27, 8 & 1
pin 26 enables air from pump
4. To lower each corner:
4.1. Left rear pins 11,9 & 1
4.2. left front pins10, 9 & 1
4.3. right rear pins 28, 9 & 1
4.4. Right front pins 27, 9 & 1
Pin 1 is power, pin 8 is air inlet solenoid, pin 9 is air exhaust solenoid
if that doesn't work, have a look around the bags, and make sure they aren't leaking, very common
Valveblock too is another place for them to leak, i'd rebuild it as a precaution!
It's possible the compressor has burnt out feeding an unending leak..
If you then leave the ECU unplugged the suspension will remain pumped up until you can find the fault.