* Underhood fuse box: This is the most common location. The fuse box is typically located under the hood, often near the battery. The relays are usually inside this box and are often clearly labeled.
* Passenger compartment fuse box (less likely): While less common for the radiator fan relay, some Cadillac models might place it in the interior fuse box, usually located under the dashboard.
How to find it:
1. Consult your owner's manual: This is the best place to start. The manual should have a diagram showing the location of all fuses and relays.
2. Look for a diagram on the fuse box cover: Many fuse boxes have a diagram printed on the inside of the cover. This diagram may identify the relay based on its function (like "radiator fan" or a similar description) or number.
3. Use a wiring diagram: If you can't find it in the manual or on the fuse box, you'll need a wiring diagram specific to your 1999 Cadillac DeVille's year, make, model, and engine. These diagrams can often be found online through automotive repair websites or forums (like Cadillac forums). A wiring diagram will show the relay's location and its connection to the fan and other components.
Important Note: When working with electrical components, always disconnect the negative battery terminal before starting any work to prevent short circuits.
