The backup light switch is installed on the housing of transaxle. Inserting the ignition key in the On position the backup lights should turn on when positioning the shift lever in reverse. If the above lights do not light up, look at the ignition switch, the GAUGE fuse, the bulbs, and wire harness. This could be caused by a faulty switch where even if the lights are on all the time even when the shift lever is not on reverse then the switch could be bad. If only one light has been switched on, check the bulb for that light and a harness. To inspect the backup light switch, first, disconnect the electrical connector located at the top of the transaxle then remove the switch by undoing the nut on top. It is recommended to make sure the plunger is depressed and check for continuity and when the plunger is released, there should be no continuity. If this switch does not work properly, replace it with removing the electrical connector and the switch from the case by unscrewing it. Before installing the new switch, apply the plunger of the particular switch with the ohmmeter across the switch terminals; there must be continuity only when the plunger is pressed. Last but not the least, place the new switch and make sure that it is firmly fixed.