0801 problem

[dave edge]

hi guys hope you can help ive hard wired my 0801 into my zafira ive used a add a fuse and wired it to my rear wipers so it turns on and off with my ignition when i start my car it turns on and shows its recording but when i turn ignition off it powers down after about 10 seconds but there is no video saved to sd card if i use it as a hand held camera with no power lead connected it records and saves video fine where am i going wrong pls help its driving me mad