2004 Chrysler Town And Country electrical system problems

I had taken the vehicle for repair on two occasions due to turn signals malfunctioning, power windows malfunctioning, and back sliding doors malfunctioning. On the first occasion malfunctions could not be enacted. On second occasion, a switch was replaced. On june 28, 2006 van was hit in rear pushed into another car and thrown into an 18 wheeler traveling 60 miles per hour and no airbags deployed.

Where to begin? 1) wiring that run along passenger side door to control rear hatch, and back side sliding door severed by opening slider door. Car can no longer be locked because the power door look system controls were cut when the wiring was cut. 2) complete loss of displays and controls in the dashboard, with no warning that it was going to happen. Everything worked in the evening, and was lost the next morning. No wipers, lights, displays, etc.