To find it, you'll need to consult a wiring diagram specific to your 1987 Cadillac DeVille. These diagrams show the relay's location within the fuse box (usually under the hood or inside the car, often under the dash) and often show the relay itself labeled or numbered. You might find such a diagram in:
* Your owner's manual: Check the electrical diagrams section.
* A Haynes or Chilton repair manual for your vehicle: These are readily available online and at auto parts stores. They usually have detailed diagrams and descriptions of components.
* Online automotive repair databases: Sites like AllDataDIY or Mitchell 1 (often subscription-based) provide comprehensive wiring diagrams.
General Search Strategy:
1. Look in the under-hood fuse box: This is the most likely place. The relays are often in a separate section or on a panel within the larger fuse box. Look for a relay that's labeled or logically located near other components related to the HVAC system.
2. Look in the interior fuse box (under the dash): Some Cadillac models locate relays here.
3. Check for a relay panel: Some vehicles have a dedicated relay panel, often located near the fuse boxes.
Without a wiring diagram, you'll have to use visual inspection, tracing wires, and process of elimination (potentially using a multimeter to test relays). This is time-consuming and potentially frustrating without proper documentation. Getting the wiring diagram is highly recommended.
