2002 Ford F-150 5.4L 4R70 trans. The temperature guage I have is digital that starts reading at 72 degrees. Below that temp it blinks 'LO'. I have been getting fluctuations in temp reading as if there may be a thermostatic temp bypass in the cooling system for the trans or I have a sending unit that is goofy. I had the trans flushed and filter changed then had the trans temp guage installed. The trans is starting to heat up faster now at these temps than it ever has since I had the guage installed. I get up to about 125 and suddenly it's reading below 70 then it climbs back up to 125 and stays there for the most. Any ideas?