Where in the 1996 town car is receiver for remote control frequency located and how do you diagnose if it bad when both transmitters are working fine with full batteries?

The receiver for the remote control in a 1996 Lincoln Town Car's keyless entry system isn't a single, easily identifiable component like a box. Instead, the receiving function is integrated into the body control module (BCM). This module is the central nervous system for many electrical functions in the car, including the keyless entry.

Therefore, you can't just replace a "receiver." If the keyless entry isn't working, despite good transmitters and batteries, the problem lies within the BCM or its associated wiring.

Diagnosing a Faulty BCM (or related wiring):

Diagnosing a problem in the BCM is more complex and requires more sophisticated tools than simply checking a single part. Here's a breakdown of steps, progressing in difficulty:

1. Check Fuses: Start with the basics. Check the fuses related to the keyless entry system in the fuse box (usually under the hood and inside the car). The owner's manual will show you the fuse layout and which fuses are associated with the keyless entry or power locks.

2. Check the Antenna: The BCM receives the radio signal from the remote via an antenna. Often this is a simple wire running through the windshield or integrated into the body. Look for any obvious breaks or damage to this wire or the antenna location itself. This is often a weak point and can cause intermittent or complete failure.

3. Check for BCM Communication: This requires an OBD-II scanner capable of accessing the BCM's data. A professional mechanic would use such a scanner to see if the BCM is even receiving signals or if it's communicating properly with the rest of the car's systems. If the BCM isn't communicating at all, it's highly likely it's faulty.

4. Test the Door Lock Actuators: If the remotes are sending signals but nothing happens, check the door lock actuators themselves. These are the mechanical parts that actually lock and unlock the doors. They can fail independently of the BCM or remote. Try manually locking and unlocking each door. If one or more are faulty, it could explain the lack of response even with a working remote and BCM.

5. Professional Diagnosis: If the above steps don't pinpoint the problem, take the car to a qualified mechanic or an auto electrician. They have the tools and expertise to properly diagnose communication issues with the BCM and related circuitry. They may be able to test the BCM directly or even reprogram it if it's not completely faulty.

Important Note: Replacing a BCM is usually expensive because it requires specialized programming to match the car's VIN and other systems. A professional should handle this unless you have extensive automotive electrical experience.