I have a BP65 fitted in my van, and it isn’t functioning as normal. The circuit doesn’t reset itself automatically as it should (has been working fine for 4 years till now). I’ve had the input tested and it is showing as recieving power, but the only way to reset it is by bridging the input and the small black wire leaving the unit. Does this mean the unit is faulty and needs replacing, or is there something else I should be looking at? Thanks.