Q: Hi i just replaced a starter on 2004 gmc yukon 2500 with 6.0 engine when i started it up my fog lights come on and when i turn it

Hello, thank you for writing in. The vehicle may be having one of many issues. If you changed the starter because the vehicle was having starting issues, it may have been the battery causing you problems. If the fog lights were turned on when the vehicle was shut off, they may have just automatically come on when the vehicle was started. It is possible for the battery to have enough power to illuminate the lights and not start the vehicle. If the battery is fine, but being drained by the fog lights, you may also have an issue with the fog lights. Further testing on the battery should be done first. Make sure the power and ground connections are clean, dry, and tight. From there if you are still having issues with the fog lights or starting, you need to make sure the fog lights are turned off, and check what voltage they are drawing when off. If they are drawing excess power, you have a parasitic draw and the source of that power draw (which can drain the battery while they are off and cause a no-start) must be found. For more help with this testing, contact our service department to schedule an appointment.