heat issues

i have 02 ram 1500 4.7l, my problem is have no heat on drivers side on face &floor. engine temp is normal, halfway on guage, when driving the defrost cools down 2 luke warm,when sittin at idle it warms up.any ideas or comments would b a great help,gettin chilly here southern ontario canada thanx:2cents:

This may be your problem.
http://dodgeram.info/tsb/2002/24-004-02.htm

have you tried replacing thermostat?