GMC Yukon XL 1500 running lights remain on permanently despite checks and relay replacement on GMC Yukon XL 1500

Some GMC Yukon XL 1500 owners report experiencing issues with running lights that remain on permanently, even after checking and replacing relays. This problem may be attributed to a faulty light switch, which could necessitate inspection and potential replacement. Additionally, some owners have identified a short circuit in the wiring harness as a possible cause, requiring careful inspection for damage or exposed wires. A malfunctioning Body Control Module (BCM) has also been noted as a culprit, and owners may need to have the BCM checked and replaced if necessary. Furthermore, issues with the Daytime Running Light (DRL) module may lead to the lights staying on, prompting inspection and possible replacement of that component. If these troubleshooting steps do not yield results, it is advised that owners consult a professional mechanic or dealership for a thorough diagnosis and appropriate solutions.