Help anyone. I have 2019 1500 classic with 5.7 hemi. I'm towing 7000 lb loaded trailer at 1200 lb total payload (with WD hitch)...I'm towing under my maximums. Yesterday climbed a 6 mile, 6% grade at 45 mph in tow/hail mode. My coolant temp hit 245 - 247 at the top. Yikes. I'm thinking no way is this normal. Gauge was halfway between 3/4 and redline..high temp coolant warning light DID NOT come on. Temp dropped quickly once I started going downhill. I'm waiting to hear from my service manager as to if this is normal...I don't believe it is. Ambient temp was 91 degrees. Again, I'm within towing specs. What's going on here? Can anyone opinion on this?
If the high-temp light didn't come on, you should be within range.
However, someone recently had an issue that only showed up while towing, it turned out haft his radiator was covered in mud from off-roading which hurt his cooling. It wasn't noticeably under normal driving, only under stress. He bought the truck used, so he had no idea the radiator fins were covered up until after he took it to the dealership. Good idea to double check your radiator just to make sure it's free of any debris.
Also, here is a good video that shows temps for extreme towing done with a current gen RAM, it should still be similar to the temps you are getting. Over 11,000 feet elevation, It is a 7% grade w/ over 10,000 lbs towing for about 8 miles. More extreme to what you were doing, but still a good comparison.
Their coolant temp at the end of 8 miles was 240F, with Oil Temp at 287F. Based on this, your coolant temp is close to theirs, but you are towing under less extreme conditions. Did you get your oil temp as well during this time? If it's similar to theirs, then you should be normal. If it's significantly lower, then you maybe got a radiator issue.
See at 9m25s on the video for final temps at the top