Owner's Problem Description
The owner reports that the high mount brake light on their 2000 Dodge Stratus is not functioning when the brake pedal is pressed. They confirmed that all other electrical components in the vehicle are working properly. The owner has been advised to check the brake light switch under the dashboard at the brake pedal to test for power. They are seeking guidance on how to perform this test and whether any special tools are needed.
Professional Technical Analysis
For a 2000 Dodge Stratus experiencing a non-functional high mount brake light, start with the basic specifications: this vehicle is equipped with a 2.4L inline-4 engine, typically mated to a 4-speed automatic transmission, with an estimated mileage of 150,000 miles. The primary symptom is the failure of the high mount brake light to illuminate when the brake pedal is pressed, despite all other electrical systems functioning correctly. This issue often stems from the brake light switch, which is commonly located under the dashboard at the brake pedal. When the brake pedal is pressed, the switch should complete the circuit, allowing voltage to flow to the brake lights. If the switch is malfunctioning or disconnected, it will not send the necessary signal, resulting in a non-operational light. Use a multimeter or a 12V test light to check for voltage at the switch when applied; there should be a constant voltage present when the pedal is not pressed and the voltage should drop to zero when pressed. The brake light switch should have a resistance value close to zero when activated. Given the vehicle's age and typical wear patterns, it's crucial to inspect the switch wiring for frays or corrosion. If the switch is found faulty, replacing it (OEM part number 4607503AA, approximately $25) is recommended. Ensuring this component works properly is essential for safety and compliance with traffic regulations.
Possible Causes
Most common causes (ordered by frequency):
- Brake Light Switch Failure: The brake light switch, located under the dashboard at the brake pedal, may be faulty or disconnected. When the brake pedal is pressed, the switch should send power to the high mount brake light. If the switch is malfunctioning, it won't complete the circuit, leading to a non-functional light. Testing for voltage at the switch using a multimeter or a 12V test light can confirm its operation. - No illumination of the high mount brake light when pedal is pressed, constant voltage present at the switch when not pressed, no voltage drop upon activation.
- Wiring Issues: Damaged or corroded wiring leading to the brake light switch can prevent power from reaching the switch or the brake light itself. Environmental factors such as moisture can exacerbate these issues. Inspect the wiring harness for signs of wear and ensure all connections are secure. - Visual inspection reveals frayed or corroded wires, loose connections at the switch.
- Brake Light Assembly Issues: The high mount brake light assembly itself may be faulty. Inspect the bulb and socket for corrosion or damage. If the bulb is burnt out or the socket is corroded, it can cause the light not to illuminate even with a functioning switch. - Inspection of the light assembly reveals burnt out bulb or corroded socket.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Initial Visual Inspection: Start with a thorough visual inspection of the brake light assembly and wiring. Look for any signs of damage to the high mount brake light, including the bulb and socket. Ensure that the connections are secure and free of corrosion.
- STEP 2 - Check Brake Light Switch: Locate the brake light switch under the dashboard at the brake pedal. Use a multimeter or a 12V test light to check for voltage at the switch. With the pedal not pressed, there should be a constant voltage. When pressed, the voltage should drop to zero if the switch is functioning correctly.
- STEP 3 - Inspect Wiring: Examine the wiring leading to the brake light switch for any signs of wear, corrosion, or loose connections. Repair or replace any damaged wiring as necessary. Ensure that all connections are secure.
- STEP 4 - Verify Operation: After completing the above checks and repairs, re-test the high mount brake light. If the light is still not functioning, consider replacing the brake light switch as a final step.
