Switch from 62-68. Note that this type of column inner slides freely in the tube and if removing and refitting or replacing the column as a whole you may have to adjust the position of the outer in its clamp brackets, i.e. slide it up or down relative to the inner, to get the indicator switch in the correct position relative to the cancelling peg, even though the switch position on the outer can be adjusted to some extent. The position of the inner is determined by the U-joint and rack.
Showing the cancelling peg screwed into the column, also the horn slip-ring.
The following pictures show the detail of a switch from a 1973. Switch in the cancelled position showing the contact fingers clear of the contact rivets. The fingers are the 'common' contact with the light-green/brown wire coming from the flasher unit, the rivets are connected to the green/red and green/white wires going to the left and right respectively corners of the car.
Switch turned to the right, stalk down and upper contact (when installed) closed. Also showing the cancelling fingers. When the switch is operated one of the cancelling fingers is moved closer to the column and the other further away. When the wheel is turned far enough from the straight-ahead a peg or cam on the steering column brushes under the finger lifting it and dropping it back with an audible click. When the wheel is turned back towards the straight-ahead position the peg or cam hits the tip of the finger pushing the switch back to the central position. In this position both fingers are clear of the peg or cam.
Switch turned to the left
Clip partially removed showing the spring (with ball behind) that latches the switch in each of the three positions
Switch turned to the left just showing one of the two ridges and two of the three grooves that are part of the latching mechanism
Indicator/turn switch in the cancelled i.e. central position, wheel straight-ahead, which puts the cancelling cam between the cancelling fingers. Earlier cars had a cancelling peg screwed into the column instead of the cam shown here. To correct the cancelling position this cam can be slid around the column (it's a tight fit, obviously) but if the peg is in the wrong place the steering has to be split at the column UJ and the relative positions of the two shafts adjusted.
Indicator not operated, wheel turned to the left, cancelling cam under the cancelling finger but clear of it
Indicator operated to the left, wheel being turned left, the cancelling cam lifting the finger as it passes it
Indicator operated to the left, wheel has been turned left past the cancelling finger, now being straightened-up again. The cam hits the end of the finger and pushes the switch back into the central position again.
The connection of the common wire from the indicator flasher and the wires to the right and left sides
The rubber bumper prior to 1977 arrangement - the indicator switch clamps to the top of the column, and the wiper switch is screwed to the indicator switch bracket.
The 77 and on indicator/dip/horn switch AAU4991, with provision to mount the wiper/OD switch AAU4992 (Leacy). No cancelling fingers being operated by a cam on the shaft, protrusions on the back of the steering wheel engage in cut-outs in the blue collar, that collar performing the cancelling function inside the switch.