1. Access the taillight assembly: Open the trunk. The taillight assembly is usually accessed from inside the trunk. You'll likely need to remove some interior trunk trim panels. These are usually held in place by clips or screws. Carefully pry these panels away starting at the edges. Consult a repair manual or online forum specific to your year and model Eldorado for detailed diagrams showing the location and type of fasteners.
2. Locate the bulb: Once the access panel(s) are removed, you should be able to see the back of the taillight assembly. The turn signal bulb socket will be one of several within the assembly. It's usually a standard bayonet-style bulb (like a 1157 or similar). Locate the socket for the turn signal – this may require some visual inspection to differentiate it from the brake light or reverse light sockets.
3. Remove the old bulb: Gently twist the bulb counter-clockwise to remove it from the socket. If it's stuck, carefully wiggle it loose. *Be careful not to touch the glass portion of the bulb with your bare hands, as oils from your skin can shorten its lifespan.*
4. Install the new bulb: Insert the new bulb into the socket and twist it clockwise until it clicks into place. Ensure it's firmly seated.
5. Reassemble: Put the interior trunk panels back in place, securing them with the clips or screws you removed earlier.
6. Test the bulb: Close the trunk and test the turn signal to confirm the new bulb is working correctly.
Important Considerations:
* Repair Manual: A repair manual specific to your 1985 Cadillac Eldorado is highly recommended. It will provide detailed diagrams and instructions, preventing you from accidentally damaging other components.
* Bulb Type: While likely a standard 1157 or similar, double-check the type of bulb required before purchasing a replacement. The old bulb should have the type number printed on it. Auto parts stores can also help you identify the correct bulb.
* Tools: You'll likely need a small screwdriver (possibly Phillips and/or flathead), and possibly a panel removal tool to avoid scratching the trim.
* Photography: Before you start dismantling anything, take pictures of how the trim pieces are arranged. This will make reassembly much easier.
If you're uncomfortable working on your car yourself, it's always best to take it to a qualified mechanic.
