* Brake System Malfunction: This is the most serious. The light illuminates to warn you of a problem within the braking system itself, such as low brake fluid, a malfunctioning brake light switch, or a problem with the anti-lock brake system (ABS) if equipped. Do not drive the car until the problem is diagnosed and fixed.
* Parking Brake Engaged: The light may also illuminate when the parking brake (emergency brake) is engaged. This is normal.
* Brake Fluid Low: A low brake fluid level is a serious issue. Low fluid means there might be a leak in the system. Have it checked immediately.
* ABS Malfunction (If equipped): Some 1994 Mustangs had ABS. If the light stays on or flashes, it indicates a problem with the ABS system. While you can still brake, the ABS functionality is lost. You should still get it checked.
In short: If the brake light is on and the parking brake is *not* engaged, it's a warning sign that requires immediate attention from a mechanic. Ignoring it could be dangerous.
