* Faulty Antenna Motor Relay: This is the most probable culprit. The relay is a switch that controls the power to the motor. If it's stuck closed, power will continue to flow to the motor even when the ignition is off. This relay is relatively inexpensive and easy to replace.
* Short Circuit: A short circuit in the wiring leading to the antenna motor could be providing a continuous power source. This is less likely than a faulty relay, but possible. Locating a short requires tracing the wiring.
* Power Supply Issue: While less likely, a problem in the car's electrical system could be supplying power to the antenna motor circuit even after the car is off. This would require a more thorough electrical diagnosis.
* Aftermarket Radio/Alarm System: If you have an aftermarket radio or alarm system installed, it's possible that its wiring is interfering with the antenna motor circuit. This is a possibility to consider if modifications have been made to the car's electrical system.
Troubleshooting Steps:
1. Check the Fuse: First, check the fuse related to the power antenna. If it's blown, that suggests a short circuit somewhere in the system. Replacing a blown fuse is a temporary fix; you still need to find and address the underlying short.
2. Locate the Antenna Motor Relay: Your owner's manual or online resources for your vehicle might show where the relay is located (often under the dash or in the fuse box). Try removing the relay. If the motor stops running, the relay is definitely the problem.
3. Inspect the Wiring: If the relay isn't the problem, carefully examine the wiring leading to the antenna motor for any signs of damage, fraying, or exposed wires. Look for areas where the wiring might be touching metal.
4. Disconnect the Antenna Motor: As a temporary measure to prevent battery drain, you can disconnect the power wire leading to the antenna motor. This is only a workaround; you still need to fix the underlying electrical issue.
If you're not comfortable working with car electrical systems, take your Caprice to a qualified mechanic. A persistent drain on your battery can damage it. Fixing this issue as soon as possible is recommended.
