I have a 2004 GMC Yukon all wheel drive, last weekend I went to start it and it acted like it had a week battery. On top of that, when it started the fog lights were on, which you have to manually turn on once the vehicle is running? This past week it has acted like a dying battery, however I had the battery tested and it is good. The truck always starts (so far) however it slowly cranks (like a dead battery) and then it gradually goes faster and then starts. I've heard battery, alternator and starter could be the problem. I don't know what it is, nor do I understand why sometimes it turns my fog lights on?
Optional Information:
2004
GMC Yukon 5.3L V8
Already Tried:
Nothing yet