Hi I have a 08 F-150 and recently my RSS has stopped working. When i start the truck and put it in reverse it will beep a few times and then the Off light glowes, when i push it, it stays on the off postion. Once i cut the truck off and restart it same thing happens... Any suggestions would be nice i have checked tailgate made sure it was shut also i checked reverse lights and brake lights ... they were good as we'll thanks ...