The 32G micro sd cards I use in my dash cam, won't work any more for some reason. When I downloaded the vid's off them and delete the content, they say there is only 1.9G available. When I put them in the dash cam, it says the storage medium is full. So was wondering, would formating them make a difference, or should I remove just a few files at a time and not the lot. Played around with one and deleted everything and now it won't even register as being there, so decided to get some advise before doing anything else. Didn't happen with 8-16G SD, but 2 x 32G have done the same thing and don't want to wreck any more until I have an answer.