Arrived on site to troubleshoot basement lighting circuit causing the breaker to trip. Once the basement lights turned on, the breaker controlling the basement lights and the living room floor outlet would trip. I went through and checked the breaker to make sure it wasn’t a faulty breaker. Once it was confirmed that the breaker was good, I started taking out fixtures connected to the basement keyless fixtures. When I took out the fixture next to the car, the breaker started to stay on. Once I connected that fixture again, the breaker would trip. I informed the homeowner that the fixture is bad and needs to be replaced. I also gave options to upgrade the lighting in the basement. Everything is working correctly.