The last week I replaced my heater core and it works great now ! But the other day I went to switch it over to cold and something made a weird sound and It won't go back to hot it stops at half way and I have to try and force it over to hot , but It won't blow cold air it's still hot ? I drive a 89 4x4 and it's the old heating controls.

 

Pull the glove box down wiggle the hot, cold lever and look to see which cable is moving that cable or blend door has to be binding!

 

Ahh yeah I think I know what's wrong know ! Thanks

 

Your welcome.

 

I always turn down the fan speed when I switch from hot to cold, there is too much tension on the cables from the blowing air.

 

Yeah the cable popped out of the bracket that holds it and it was getting caught , easy fix and works now