Air ride suspension

So I was parked in a parking lot sitting and then people opened the doors and got out. Before I could put the car in drive a message of 'stop vehicle to low' appeared. Front is all the way down now and newly installed compressor still will not come on. What is wrong? All the fuses and relays appear to be good. Reading of only about four volts at wiring to the compressor. Can jump compressor with a different power source and it will run, still does not air up front of car.