Unlike most cars, SUVs, and trucks, where the side marker lights are located on the fenders near the front doors, the side marker lights of some Lexus IS300 models are found on the sides of the bumper, near the wheels. (Other Lexus IS300 models have side marker lights both on the bumpers and on the front fenders.) If you are having trouble with your Lexus IS300 side marker lights regardless of what model you own, here are some practical solutions that will really come in handy:
Accessing the side marker lights is fairly easy. Whether the marker lights are located on the fenders or on the bumpers, you need to remove the wheels and the fender liner. Remove the sockets that hold the liner in place and pull the liner back to gain full access to the back side of the side marker lights. Once you can reach the lights, you can start whatever work you want to perform with them. Note: The rear bumper doesn't have a bumper liner.
There are three possible reasons why your side marker lights are not working. First, your fuse is blown. Second, your lights are busted. Third, there is a problem with the wiring. Before working underneath the car, check the fuse box and locate the turn signal light fuse. If it is blown, replace it with a new one. If the fuse is blown, all your signal lights won't work. If side marker lights are busted, the other turn signal lights should be working. If the hazard switch is on and all, but the side marker lights are not working, it is either busted or there is a problem with the wiring. Access the side marker lights as explained above. Check the wiring using a voltmeter. Remove the bulb and test the socket for electric current. Check the bulb if busted. Repair the wires or replace the bulbs. This procedure applies whether you are working on the side marker lights on the fenders or on either of the bumpers.