The module in the trunk by the battery (big sucker) has failed on mine. It failed years ago. Took it apart and cleaned all the contacts, resoldered some cold solder joints. But the weakest point is the wire harness that plugs into it. Be gentle. Leave it plugged in while you work on it, I recommend. If you screw up that harness, you have to rip out the entire body harness. You can buy one new for $3500.