My wife's 2012 grand Cherokee with a Hemi has selec trac on it. Well, the other day it starts flashing for no reason on selections such as sport, snow, etc. took to dealer to hook up and nothing is showing. They said could be bad switch so instead of spending $600 for labor and switch I got a tested one from junk yard and put in. It is still flashing??? Anyone heard of or seen this? Am I missing something? Frustrated! Thanks for any help!