Ford Repair: 2004 Ford Expedition, fuse panel, electrical tester

Question
Where is the air line splice identified as under the master cylinder in the Suspension Air system? My rear bags wont inflate and compressor is not starting. I cleaned the connector at the relay and it appears fine. I have no electrical tester.

Answer
the air line is located on the right side of the engine, as if your looking at it. there's a couple . things i'll need you to check, in the fuse panel in the engine comprtment is the fuse for the compressor. be sure this is good. the connector at the relay, pulley the shielding back from the harness and insoect for corrosion about 6" back from the connector. assuming all of this is o.k. then replace the relay