Hey there man. That's a good question. If you don't drive long enough to get it warmed up (I don't either now that I work 5 minutes away from home lol so don't feel bad), there's nothing wrong with just letting it idle for a few until it reaches operating temp, usually within about 10 minutes, and then check it. I'm not sure how accurate the cold check would be as I've always let it warm up.
Hey thanks for the welcome, I had a question about checking the fluid in my ram. I just changed trans filters and dropped the pan, did basically what the write up on the forums said. Anyways my ram never reaches optimal temperature to check the trans fluid how accurate are the cold checks. I added 7 quarts of atf+4. The hottest I had the trans at was 145°F and it was a little lower than half way between the two hot holes and cold ones any advice?