All of the following should be investigated before ordering a replacement RV or Motor Home window:
Knob stripped - The simplest reason that a torque RV window will not operate is that the knob is stripped. If the knob turns, but the RV window does not open, remove the screw holding the knob to the operator shaft, pull the knob off & try to rotate the shaft with pliers, be careful not to damage the shaft. If the RV window opens, order a replacement knob.
Vent binding - If the knob & operator appear to be turning properly, but the vent will not open, it is possible that the vent pane is catching the frame at one side. Check this by having a helper outside the unit observe as you turn the knob, have your helper assist to free the inside that sticks, if it pops free & the RV window opens, there are a few simple fixes to try:
Check for caulk or other materials, which can be removed to permit greater clearance
Check to determine whether the vent is centered in its opening, if not, gently tap it to the center using a wooden block and mallet.
If theses solutions do not fix the problem, the RV window may have been improperly installed, check this by removing the RV window from the wall and operate in the non-insulated mode, if the RV window works properly, the RV window was installed while racked or twisted. Reinstall the window with the vents closed, but not tight, generally, the RV window will be flatter in this mode than when closed really tight. If this technique is not successful, the RV window will probably have to be replaced.
Defective operator - After several years, the gear mechanism inside the operator may wear out, it the operator shaft turns, but the torque tube does not, the operator must be replaced, Check out the instructions on operator replacement.
Linkage problems - There are several places where interference or other problems can occur with the linkage mechanism, Check for:
All connection secure (no E-rings missing, no rivets broken)
Torque tube intact (not broken or bent)
Interference (inadequate clearance between moving parts)