* Low brake fluid: This is the most frequent cause. Check the brake fluid reservoir (usually a clear plastic container) under the hood. If the fluid level is low, you have a leak somewhere in the system – a potentially serious problem requiring immediate attention.
* Parking brake engaged: Make absolutely sure the parking brake is fully released. Sometimes it can be partially engaged, triggering the light.
* Brake light bulb(s) burned out: A burned-out brake light bulb can trigger the indicator light on some models. Check all your brake lights (taillights and center high-mounted stop lamp (CHMSL)).
* Faulty brake light switch: This switch is activated when you depress the brake pedal and completes the circuit to illuminate the brake lights. If the switch is faulty or worn, the light may stay on.
* Faulty brake pressure sensor: Some S10s might have a brake pressure sensor that monitors the pressure in the brake lines. A faulty sensor could trigger the light.
* ABS (Anti-lock Braking System) malfunction: If your S10 has ABS, a problem within that system could illuminate the brake light (often along with a separate ABS warning light).
* Master cylinder problems: A failing master cylinder can cause low pressure and trigger the light. This is a serious issue.
* Wiring problems: Damaged or corroded wiring in the brake light circuit could cause intermittent or constant illumination of the brake light.
What to do:
1. Check the brake fluid level immediately. Low fluid indicates a leak. Do NOT drive the truck until this is addressed.
2. Check the parking brake. Make sure it's fully disengaged.
3. Inspect brake light bulbs. Replace any burned-out bulbs.
4. If the problem persists, take your S10 to a qualified mechanic for diagnosis and repair. Ignoring a brake warning light can be dangerous. The problem may be minor, but it could also be something that renders your brakes ineffective.
Don't delay getting this checked. Driving with a brake warning light on is risky and could lead to an accident.
