My 2005 manual challenger is in and out of 4L and 4H quite often and slides in no dramas. Today I was backing a trailer up a small incline on marshy grass and starting spinning the back wheels. So naturally I selected 4L to see if the front would help push it up, and started spinning again only on the back wheels. I was full locked so I straightened the wheel and tried again but still no drive in the front. I tried the basics (Being taking it in and out of 4x4) and could not get any drive. The 4x4 light always flashes even in 2H but it doesn’t bother me just figured a censor had busted from mud or something, but today the light didn’t come on at all. I think it could be electrical but I haven’t got a very mechanical head on my shoulders so I’m here asking anyone if they know what the problem could be, I’d appreciate someone else’s thoughts on it before I go to a mechanic and get ripped off if I could fix it myself. Cheers!