Originally Posted by wmatos1001
Kevin mine has the same issue. Turns out it was the linkage cable. It is hung up/stuck somewhere along the line between the hot/cold lever and the heater box. I haven't solved the cable but in summer I manually moved the heater box to "cold" setting and it improved the heat flow quite a bit. Obviously these 90's throw off cabin heat of their own but it helped a lot. Then in Winter I just pop the hood and move it back to "hot". On the box there is no hot cold label but just move the control to its opposite position and you should be good to go.
I tried that and my cable seems to be working perfectly.. I am now going to research the seal failure option....
When driving and moving the cable to the "cold" position, it certainly reduced the hot air coming through the defroster vents but.....
Think Category 1 hurricane vs Category 4, or EF1 vs EF4 for those of us in the Midwest...
Of course, if anyone knows this seal solution or test for it as I search, kindly ding me!!