Hello

Anyone that can help me with ideas would be appreciated.

On Monday night I parked my 3.3 Grand Voyager as normal on my driveway at 10.30. At 8.30am the very next morning I tried starting the car which was turning over but wouldn't start. The headlights came on although the switch was turned off. There was no dash lights at all. A friend came over with a battery indicator which was around 12volts. We tried jump starting it but even that couldn't start the car. I eventually got it towed to the local garage as Chrysler couldn't look at it until next week. They've had it for three days without success. Changing the battery looking for a corroded earth under the fuse box. They've taken the dash out and checked the wiring one by one and still can't get to the bottom of it. They are now getting it recovered to a Chrysler garage as they are unable to diagnose what's wrong with it. They can't get the car to talk to any diagnostic equipment. Help.