Brake Switch (Cruise Control): Testing and Inspection

Perform this test only when brake application will not disconnect the speed control system.

1. Check operation of stop lamps by applying approximately 6 lbs. of pressure to brake pedal. If more than 6 lbs. is required, check brake pedal actuation and stop lamp switch.
2. If stop lamps do not function properly, check bulbs, circuit fuse or stop lamp switch.
3. If stop lamps function properly, check for battery voltage at 6-way connector using white wire w/purple stripe.
4. Depress brake pedal until stop lamps are illuminated. Check voltage at red wire w/black stripe on E-Series models, or the light green wire on Bronco and F-Series and Ranger, Bronco II, Explorer and Aerostar. The difference between the two voltage readings must not exceed 1.5 volts. If voltage is greater, a high resistance exists in the circuit and must be and corrected.