One problem related to wiring has been reported for the 2007 Kia Motor Optima. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Kia Motor Optima based on all problems reported for the 2007 Optima.
Vehicle burns out blinker bulbs and headlights at an extremely accelerated rate: one a month. Additionally, the wiring harness is heated to the point of being melted. This is a fire hazard. I believe this may be a voltage regulation or ground issue.