Also test the switch. I've had issues with the switches on my 06 Challenger. The blower for example wasn't working and it turned out to be the switch. I was able to disassemble it, clean the contacts, reassemble it and it's been working ever since. Also my courtesy lights occasionally don't come on, but after cycling the switch a few times they usually work. So, it's likely the same problem. A word of caution though, there are many small parts, springs etc inside the switch so open it with care! For me it was trial and error to get it back together properly. This is all assuming the 08 uses a rocker switch like the 06.