do me a favor.. turn your hazard flashers on.. walk around the car and verify the lights are flashing at each corner.. don't just look at the dashboard.. then reach in and turn on the parking lights. walk around the car again.. see if the lights at all 4 corners are working as designed.. medium bright to bright.. if one goes DARK instead of lighting up. you have a bad ground on that bulb circuit.. do the same test with the headlights and hazard flashers on..

why am i having you waste your time walking around the car.. because this is how mechanics who know what they are doing perform a diagnosis..

i can almost bet that when you turn your headlights on. one of the turn signal indicators in the dashboard turn on solid ..

the front parking and turn signals ground at the connector under the side of the battery tray.. http://i.imgur.com/tVCVNlB.jpg

this G102 ground splice needs to be unbolted.. the ring terminal wire brushed.. the mounting bolt wire brushed.. the mounting surface wire brushed.. you can use either spark plug anti seize on it to prevent additional corrosion as you can buy a small package of that for a buck and a half.. i usually use white lithium grease.. but i have a big squeeze tube. you will also want to extract the end as shown in that image to examine it for corrosion.. i would not use spark plug anti seize in that i would clean it with a wire brush.. some electrical contact cleaner and pack it with white lithium grease.. then work the connector in and out a few times and then latch it in.. you may want to print these three images.. they are very close to how your car is wired.. http://imgur.com/a/FUGYu

the turn signal switch connector is accessible under the dashboard. you can actually probe the wiring there to verify the power is coming out of the switch.. you are not the only person having similar issues. please post what you find.. take pictures post them to imgur.. post what it took to fix it. and hit the solved tab off to the right..