Where is the theft deterrent module on a 1995 Buick Regal 3800 V6?

There isn't a single, easily identifiable "theft deterrent module" in the way some modern cars have a dedicated ECU for that purpose. The 1995 Buick Regal's theft deterrent system is integrated into the car's various electronic control modules (ECMs). The primary components involved would be:

* Body Control Module (BCM): This module is the heart of the system and manages many functions, including the alarm, door locks, and potentially immobilizer functions (if equipped). Its location varies slightly by model year and trim, but it's typically under the dashboard, possibly behind the glove box or under the steering column.

* Engine Control Module (ECM): While not solely dedicated to theft deterrence, the ECM plays a significant role if the car has a passive anti-theft system (like a transponder in the key). The ECM is typically found in the engine compartment, often mounted to the firewall or inner fender.

In short, you won't find a box labeled "Theft Deterrent Module." Any troubleshooting or repair related to the theft system would involve diagnosing issues within the BCM and ECM. A professional mechanic with diagnostic equipment would be needed to properly assess and resolve problems with the anti-theft system of a 1995 Buick Regal.