I have a 1999 4.6 HSE and I don't know what to check for this problem. My heat/ A/C selector buttons are not switching the air blowing out to anything but the main dash vents (ie I cant get heet to the floor or the defrost) hopefully someone here can give me some advice on things I can check myself before the dealer bends me over for another $1400.00

Thanks in advance

 

Well the motor that moves those doors would be called the Mode Door. Most likely you have an issue with the actuator itself. I am not sure where that actuator is located on your model, but it is going to be attached to the HVAC box behind the dash. Once located you can move the position selector and see if the motor moves.

 

sometimes its the blend door motors,sometimes the heater box assy is warped and will jam the blend door motors... then you will need the whole heater box assy,this is what you need to do,if you feel comfortable doing it,remove rs srs bag,glove box assy center console assy,then you will be able to see the heater box,remove the upper right side blend door motor,next manually move the lever that the blend door motor moves if it moves easy and smooth chances are the box is ok,if it is tight or has a tight spot then it needs a heater box assy...this is a big job take your time...good luck!

 

Wouldn't the blend door be an issue of hot and cold? I believe the op was refering to changing the position the air comes out of. Correct me if Im wrong.

 

Yes I only get air blowing through the main dash vents not the floor, defrost or any other.

 

the distibution motor the one on top right side,controls where the air is blowing not the temp,this is the one that usually gets jammed as a result of a warped box/blend door motor....it will still throw a code for dist motor o/c or s/c....basically these motors come as a 3 pack,they are connected by one connector,they are called blend door motors,right and left sides and a distribution motor,you can de pin each one if you want and replace the one that is bad or replace all of them at one shot