HVAC works in summer not winter

[HOBrian]

I thought I had a blend dooor issue last winter and waited for the summer to tear in into this POS. Last winter I could not have floor only air. #@$%! If I placed the knob on floor only I would get 20% floor and 80% defrost. My fix last winter was to take some shop towles and cover over the defrost vents. Like I said I waited until summer to fix it and when summer came the problem was gone 100% Fast forward to todays drive to work and BAM put it on defrost for some help with the light snow and sleet and then turned it to the floor and NOTHING#@$%! I am at a loss for why it works in the summer and not winter. I do not want to go diving into this thing if it is something simple. So guys please tell me this is going to be easy!!!!

 

[rbattelle]

Yikes. I wonder if you've got a broken door, but differences in the path through the evaporator allow seemingly normal operation in summer whereas through the heater core things are fouled up.

Try turning to cold air and see if the behavior matches what it did during the summer.

Ryan

 

[HOBrian]

Everything worked last summer with no problem. Defrost worked, floor worked just like it should! Now of course after work yesterday and on the way to work this AM the HVAC worked with no problem again... I think it might be a lazy motor not doing its job.