southpawslingr1

The bypass goes from the front radiator hose to the freeze plug all the way on the back of the block.

stephan.laun

Get a Cummins thermostat. Mine did the same thing with parts store thermostats and Dodge thermostats. Remeber Dodge makes it CUMMINS powers it....

Totallyrad

It could easily be just a thermostat but just for fun you might try to read the temps at different locations with a heat gun. I don't know anything about the bypass you've installed. Was this an older mod or one you just installed? If it was a kit, would you post a link to it's location so we can look at it? Another thing you can try is to cover the radiator with cardboard and let the truck warm up. You may have to add a little rpm to get it there. Watch the temp gauge to see if the thermostat is cycling. Again, if you have access to a heat gun you can verify the results.