If the mirrors do not move when you turn on the adjustment:
First, you should check the fuse (chapter "Body electrical system").
Then remove the switch (fig. top right) and check it according to the diagram (see in this chapter).
Left: The high frequency speaker (1) is screwed separately with two screws (arrows) to the door trim.
Right: The switch for the electric mirror adjustment (1) is secured at its upper edge with a plastic retainer (arrow). At its lower edge, it is screwed with a hexagonal bolt (2). The bolt is accessible after removing the heater switch trim. How to do this is described in the chapter "Lighting".
If the switch is OK, the mirror itself should be removed to make the control motor connections accessible (Chapter "Body elements").
When the ignition is on and the switch is pressed, is there voltage supplied to the engine contacts? Is the ground connection OK?
If the answer is yes, then the fault lies only in the engine. Unfortunately, it cannot be purchased separately, but only in a set with a mirror.
However, you can temporarily adjust the mirror by hand.
If the mirror heating does not work, check the current path from the rear window heating switch using the corresponding electrical diagram.