I have a 98 GMC 3500. I was pulling into the parking lot at home and realized that the front axle had just engaged. I could tell by the sound of the gears and the 4x4 indicator light lit up. I put it in 4HI to see if it'd unlock but it didn't. It's still in 2wd but the front axle stays engaged. Has anyone had this problem or knows what it might be?! I'm guessing it's the 4x4 switch. Someone told me about it once but I can't remember where it is.