FixVault

Brake Light Switch Test

NOTE: This test should be performed whenever brake application will not disengage speed control system. On vehicles with M/T, ensure that clutch switch is working properly before performing this test.
  1. Check for stop light operation with a maximum brake pedal effort of 6 lbs. (2.7 kg). Check brake pedal actuation and stop light switch if pedal effort required is excessive.
  2. If stop lights operate correctly, check battery voltage at 6-way connector Black/Green wire on Vans and White/Purple stripe wire on Bronco and Pickups.
  3. Depress pedal until stop lights are on, and check voltage at 6-way connector Red/Black wire on "E" series and Lt. Green wire on Bronco and "F" series Pickups. If voltage readings differ by more than 1.5 volts, high resistance exists in stop light circuit and must be corrected.
  4. If stop lights do not work, check stop light switch, supply circuit, fuses and bulbs for correct operation.