Some do-it-yourself repairs are simple enough and most service centers and repairmen understand that everyone tries to save money. Some repairs that seem easy on the surface however, may be more complex. The Highlander has some things that fit this category, like your turn signals.
Check each of the four bulbs to see that they are working. If one bulb is blown, it is enough to give the symptoms of a bad flasher or one that is about to go bad. If one of your lights is out, replace the bad bulb and recheck the operation of the turn signals.
Lie on your back in the driver's side floorboard and look up under the dash to the left of the steering column. Using a flashlight, find a square plug in device. Turn on the turn signal, place your finger on the device and feel for any clicking or movement inside the device. The movement or clicking will be the indicator that you have found the correct relay. A second check is to turn off the turn signal and turn on the hazard lights. You should still feel the clicking. The same flasher handles both the turn signals and the hazards.
Reach and unplug the relay and replace it with the new flasher and relay. Be sure to plug it in correctly and don't get the orientation messed up.
Start the Highlander and test all four turn signals and the hazard lights.
