Hello & Welcome to Just Answer,
Sorry to hear of any issue you are having with your device.
May I ask what happens when you connect the device to the Vehicle Power adapter - and not the computer?
Also, make sure you have power coming from the Vehicle power SOCKET when you try this (some vehicles need to have the ignition turned ON - for power to come from the power sockets).
I see it has been a few days and I just wanted to follow up to see if you have any more questions concerning this issue or if the issue was resolved.
I look forward to any further questions or results that you may have.
Thanks, ***** *****--. .-(im)