The start-inhibitor switch is located at the rear of the selector lever housing.

 

Some switches also incorporate the reverse light switch and these have four terminals - two for the ignition/starter circuit and two for the reverse light.

 

Other switches have only two terminals and the reverse light switch in this case is a separate unit which is screwed into the reverse check plunger bore in the front of the transmission casing.

 

When the start-inhibitor switch is functioning correctly, the starter will operate only when the selector lever is in the 'N' position.

 

If the starter will not operate in the N position, or if it operates in any other selector positions, then the switch requires adjustment.

 

The reverse light switch (where incorporated) should also operate only when the selector lever is in R.

 

Before attempting to adjust the switch, check the adjustment of the selector cable and the transverse rod as described above.

 

Adjusting the Start-inhibitor Switch

1. Place the selector lever in N and disconnect the electrical connection from the switch

 

2. Slacken the switch locknut (arrowed on illustration).

 

3. Connect a small battery and test lamp across the 2 and 4 terminals (red/white wiring connections) on the switch

 

4. Unscrew the switch almost out of the housing, then screw it in again until the test lamp just illuminates and mark the position of the switch

 

5. Continue screwing in the switch noting the number of turns required, until the lamp just goes out

 

6. Remove the test lamp and battery and unscrew the switch from the housing half the number of turns counted

 

7. Tighten the switch locknut and reconnect the electrical leads to their respective terminals

8. The ignition/ starter circuit leads can be fitted either way round to the 2 and 4 terminals, and the reverse light leads (where fitted) to the I and 3 terminals.

 

9. Check that the switch functions as described above

 

Note: If the switch still does not operate correctly, check the switch wiring and connections before renewing the switch.

 

Source: http://www.reizendemoke.be/techniek/manual/autotran/1.htm