Truck overheats when pulling a load and I use the turbo hard on a hill on 1999 Dodge Ram 2500

on the flat or cruising it works fine, just heats up when you get into the turbo hard

Asked by for the 1999 Dodge Ram 2500
I have a Ram 2500 diesel and I had trouble with overheating, especially since I pull a fifth-wheel. I even had a heavy equipment supervisor tell me I probably needed the radiator boiled out! Well, come to find out the radiator was clogged with bugs, i.e. insects! Guy took over an hour blowing the radiator with air and have had no overheating since!