Are you running the 185 stat from cummins or the 192 stat also from cummins made for dodge?

 

What thermostat you use? Alot of people have problems with aftermarkrt thermostats, put a cummins thermostat in and see if that fixes you problem.

 

Im running it on the tow haul...

Im running a 200degree aftermarket thermostate... I havnt been able to find one that is any cooler.

 

There is a 185 available from cummins that will make your truck run much better and keep the fan from coming on as much. I don't have the part number but if you do some digging for "185 Stat Cummins" I'm sure you'll find discussion of it somewhere.

 

def agree with the 185 cummins thermostat