Chart No. 6-1, Stop Light Switch Wiring Circuit

When the brake pedal is depressed during constant speed travel, the stop light switch contacts for the cruise control system open, creating an interruption in the signal to the actuator electromagnetic clutch, cancelling the constant speed travel.
The flow of current is from the battery to fuse No. 17 of the junction block, stop light switch, to the control unit.
Test terminal 3 on 1990 models or terminal No. 15 on 1991 models, stop light switch (load side), when the brake pedal is depressed. Voltage should measure 12 volts.
Test terminal 3 on 1990 models or terminal No. 15 on 1991 models, stop light switch (load side), when the brake pedal is not depressed. Voltage should measure 0 volts.
On 1990 models, test terminal 11, stop light switch (power supply side), with the brake pedal depressed and when not depressed. Voltage should measure 12 volts.