replaced thermostat and filled rad
poor heat from heater in 1999 durango the rad is full on 1999 Dodge Durango
could be a bad heater control valve if appl. to this model or heater controls. seek a diag and insp
2 more answers , 2 more comments
possibly a blocked heater
not that ...wonder if there is some sort of valve on heater hose...hoses are colder than rad hoses
Do you have any residue on the inside of windshield, or any sweet smell coming from the the passenger side ,just below the glove box? theres a very good chance the heatercore is done.