* Low brake fluid: This is the most frequent reason. Check the brake fluid reservoir (usually a clear plastic container near the master cylinder under the hood). If it's low, you have a leak somewhere in the system which needs immediate attention. Driving with low brake fluid is extremely dangerous.
* Brake light switch: This switch is located near the brake pedal and tells the car when the brakes are applied. If it's malfunctioning (stuck on), the brake lights will stay illuminated. It's a relatively inexpensive and easy part to replace.
* Faulty brake lights: A burned-out bulb might seem counterintuitive, but a shorted bulb can sometimes cause the light to stay on. Check all three brake lights (two on the rear and one in the center of the high-mounted stop lamp).
* Wiring issues: Worn or damaged wiring in the brake light circuit can cause a short circuit and keep the brake lights on. This requires a more thorough inspection of the wiring harness.
* Master cylinder failure: While less common than the above, a failing master cylinder can also cause the brake lights to stay on, usually along with other brake problems like spongy brakes or a hard pedal. This is a serious issue and requires immediate professional attention.
* Parking brake partially engaged: Though less likely to keep the brake light *constantly* on, a parking brake that isn't fully released could cause a slight electrical connection that keeps the lights on. Try fully releasing the parking brake.
What to do:
1. Check the brake fluid level immediately. Low fluid is a serious safety concern.
2. Check all brake light bulbs.
3. Inspect the brake light switch. It might be visibly damaged or stuck.
4. If you're not comfortable checking these things yourself, take your Beretta to a mechanic. Ignoring a brake light that stays on is unsafe.
Don't drive the car until you've identified and fixed the problem. A brake light staying on almost always indicates a problem that could lead to brake failure.
