Hello, the input of the camera is 5V/2A, Please use the original car charger.
Please unplug two rear cables and exchange the back cameras or cables, then plug one back camera at a time to test.
How long have you been using the camera?
Do you mean the camera can't detect two back cameras?
Were two back cameras connected stable before?
Please unplug two rear cables and exchange the back cameras or cables, then plug one back camera at a time to test.
May I know where you bought the hardwire kits?
If it is not a hardwire kits issue, you can check the ACC wires are installed correctly or not, normally it requires a 5V signal from the ACC cable while the car is started.
Use only the G-sensor to detect is also not a good option, it may not record will while something happened. You can use the time lapse recording, the file size is much less.
If you use Auto event detection mode, the rear camera is very sensitive, even there is a light change may cause the camera recording. But anyone have recorded is better than nothing recorded.
If you can replace the supercapacitor, we can send a new to you. The supercapacitor broken issue may happen, if this happened, it will corrupt the last file, user can switch .ts format to avoid this issue.
Could you please share a video with us? You can upload it to WeTransfer.
Do you use the original cable and car charger? Do you power the dashcam directly through the camera body or the Gps module?
We suggest you try using a power bank to power up the dashcam.