I raised a ticket with the manufacturer and another with the supplier. I too would have thought the odo should not be resetable.
The fuel reading might be because I'm using the 12v as per instructions (white) for power to the unit rather than 10v regulated (green). Will try that later if it stops raining ever.
I'm 99% sure the fuel gauge on these doesn't use an external regulator, it's also partly why I raised the question of Earthing.
That's correct, it uses 12v.
