Stoplamp Switch, Mechanical

The mechanical stoplamp switch assembly is installed on the pin of the brake pedal arm, so that it straddles the master cylinder push rod. The switch assembly is a slip fit on the pedal arm pin, and the switch pressure plate mates with the flat on the master cylinder push rod. The switch assembly travels with the pedal arm but maintains alignment with the flat on the push rod at all times.

The brake pedal arm pin and plastic bushing has a designed in clearance with the eye of the master cylinder push rod. Because of this clearance, whenever the brake pedal is pushed forward, the stoplamp switch frame moves forward pulling the whole assembly forward. During that movement, the push rod flat pushes the switch pressure plate and actuating pin rearward, closing the switch contacts. This completes the circuit to the stoplamps.

When the brake pedal is released, the spring in the stoplamp switch returns the actuating pin to its normal position and the circuit to the stoplamp opens.

Removal

NOTE: Locking tab on connector must be lifted before connector can be removed.

1. Disconnect the wire harness at the connector from the switch.

   NOTE: Since the switch side plate nearest the brake pedal is slotted, it is not necessary to remove the brake master cylinder push rod and one space washer from the brake pedal pin.

2. Remove the hairpin retainer, slide the stoplamp switch, the push rod and the nylon washers and bushing away from the pedal, and remove the switch by sliding the switch up/down.

Installation

 CAUTION: Do not substitute other types of pin retainers. Replace only with production hairpin retainer.

1. Position switch so that the U-shaped side is nearest the pedal and directly over/under the pin. Then slide switch up/down trapping the master cylinder push rod and blade bushing between the switch sideplates. Push switch and push rod assembly firmly toward brake pedal arm. Assemble outside white plastic washer to pin and install hairpin retainer to trap whole assembly.

   NOTE: Stoplamp switch wire harness must have sufficient length to travel with switch during full stroke of pedal. If wire length is insufficient, reroute harness or service as required.

2. Assemble the wire harness connector to the switch and install the wires in the retaining clip.

3. Check stoplamp switch for proper operation.