I am having trouble getting my air springs to re-inflate after replacing one of them. I suspect it's either the solenoid valve next to the compressor blocking air flow or one or both of the level sensors. Not sure which yet, but I want to bench test the solenoid valve if I can, rather than just shell out $200+ and hope for the best. The compressor is working fine BTW. Is there a way to bench test the solenoid? Either by taking ohms readings with a multimeter or by jerry-rigging some wires to a battery and seeing if it opens? What do the wire color codes correspond to? I presume the black one is the ground, and the other two swing the valve left or right, or if not charged, to a central detent position. Can help? Thanks.