Kia Troubleshooting Questions? Ask a Mechanic
It could be a few different things. Since it was hit in the left front you should start by checking the grounds. There are 2 ground bolts with wires for the headlamps among other things in the left front. You'd want to check to make sure there are no broken wires, no corrosion, and that the bolts are tight. You should be able to access them by removing the left front wheel and the plastic wheel well. I've attached a picture. Aside from that, the only other common thing that the turn signal and head lamps have is the multifunction switch itself (the switch that you turn the lights on with that also turns on the turn signals). Hope this helps.
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Here is the picture.