To find potentially relevant relays, you'd need to consult a wiring diagram specific to your 1997 Ford Expedition *with the air suspension option*. These diagrams usually show the relay locations in the underhood fuse/relay boxes. You'd look for relays associated with the air compressor, suspension control module, or related circuits. However, even with the diagram, it may be difficult to positively identify relays solely for air suspension.
Instead of searching for a specific relay, if you're having air suspension issues, it's best to:
1. Check the fuses: Start by checking the fuses related to the air suspension system in the underhood fuse box. Your owner's manual should list these.
2. Consult a wiring diagram: A factory service manual or a wiring diagram specific to your year and model Expedition (with air suspension) is crucial for proper diagnosis.
3. Use a diagnostic scanner: A code reader or OBD-II scanner can retrieve diagnostic trouble codes (DTCs) related to the air suspension system, pointing you to the faulty component.
4. Professional Diagnosis: Air suspension systems can be complex. A mechanic familiar with these systems is the best resource if you can't identify the problem yourself.