To replace the lamp back up switch on the ZF S6-650, lift and support the vehicle in an appropriate manner. For the 6.6L models, you disconnect the back up lamp switch electrical connector, and for 8.1L models, you disconnect the back up lamp switch electrical connector. Then, got rid of the back up lamp switch. When you install the new switch, make sure to tighten its 20 Nm (15 ft. lbs.) according to the fastener notice. For 8.1L engine, the restoration of the back up lamp switch electrical connector while for 6.6L the restoration of the back up lamp switch electrical connector before lowering the vehicle.