When you are ready, test the back up light switch and check the No. 19 7.5-amp fuse in the under dash fuse relay box. Put the shift lever in Reverse and turn the ignition switch to On, then turn the ignition switch off and the back-up lights should go on, then go off. If back up lights don't come on, check back up light bulbs at the tail light assembly. If the fuse and bulbs are both good, look for a back-up light switch mounted on top of the transaxle and trace the leads back to the electrical connector then unplug it and test with a continuity (ohmmeter) between the two terminals. Continuity should be present when the shift lever is in Reverse; and continuity should not exist with the shifter in any other gear. If it fails this test, it will have to be replaced. Set the switch operational, but still have the back-up lights not working. Trace the circuit between the switch and the fuse block if voltage is absent. Trace the circuit from the switch to the back up lights, if power is present. Pull out the electrical connector, unscrew the switch, toss the old washer, place in the new switch, and screw on the new washer, then reconnect the connector.