Truck Repair: heater problem, vacuum inlets, upper radiator hose

Question
i jave a 1999 dodge 1500 pu  heater blowingout just barley warm air   i have changed the heater core    changed the thermostat (195degree)    temp gauge shows temp at 190 to 195    took heater box out and open each door holding my finger over the vacuum inlets    they stayed open till i removed my finger    replaced the heater controls on the dash   if you turn the heater controls all the vents seem to be working      i put cardboard over the radiator   took it down the road   temp hand did not change   HELP  PLEASE

Answer
Hi Matt,
Feel the heater hoses, and if they are both hot, say about the same temp as the upper radiator hose, then air flow through the heater housing is almost surely the problem.

If both heater hoses are not hot, then it is a coolant flow problem.

Is there a cable, or vacuum controlled coolant control valve in one of the heater hoses? If so, make sure it is opening.

Van