Replaced the defrost timer. It was not located where the parts explode suggested in the thermostat control box which is located in the upper right corner of the liner. It was in fact outside the freezer compartment on the back lower left support (when looking at the back of the freezer). It is secured with 2 sheet metal screws with a 1/4 hex head. The manual override dial is visible through a punched hole in that support. Just remove the 2 screws, disconnect the electrical connector. Then reverse the procedure to install the new timer.