Hi any advice on the invisible camera I installed on my travel trailer, it works sometimes sometimes not,last week it was working great cut in and out a few times stopped working, pulled over tried unplugging and sit for a while and rehook up but no go said not camera present ? I have had this camera for a year now it has never worked consistently?,I have ensured it is connected well,sprayed the ontacts with slap shot,it just can't get to work all the time ? Any help would be greatly appreciated