I have just purchased a 2008 Liberty Heritage wagon with the auto. It had a cooked engine which I have replaced and I am readying it for a roadworthy inspection. The only item left on my list is the reversing lights won't work. I have checked the fuse, globes and the wiring into the tailgate and all OK (no power at the globe holders). Does the gearlever position sensor trigger the lights or something else(the dash shows all the gearlever positions OK). I don't have a wiring diagram. Any suggestions where to go from here?