However whilst the diagram indicates there are seven electrical connections to the switch, a look at a switch will show that several of these are paired giving just the four electrical connections that one would expect. The picture below shows the brown and the next spade (non-factory wiring) being paired, then the next two terminals are paired (again non-standard accessory wiring), then the white/brown for the starter is on its own, then the last two are paired for white ignition wires (non-standard wires on the second of these). (Photo Peter Mayo)

1968/69 North America

With the key inserted and turned to the first position (ignition) terminals 3 (brown) and 2 (white) are connected together.
When turned to the 2nd position (start) all three terminals are connected together.
With the key turned fully left or out of the lock all of the terminals are isolated.

1969/70

With the key inserted and turned to the first position (accessories) terminals 1 (brown) and 3 (dealer wired colour can vary) are connected together.
When turned to the 2nd position (ignition) terminals 1, 3 and 7 (white) are connected together.
When turned to the 3nd position (start) terminals 1, 7 and 6 (white/red) are connected together and terminal 3 is isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

Again refer to the photo above for the physical arrangement.

1969/70 North America

When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire, its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock terminals 1, 2, 3 and 5 are isolated.

1970/72

With the key inserted and turned to the first position (accessories) terminals 1 (brown) and 4 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 1, 4 and 2 (white) are connected together.
When turned to the 3nd position (start) terminals 1, 2 and 3 (white/red) are connected together and terminal 4 is isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

1970/71 North America

When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire, its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock terminals 1, 2, 3 and 5 are isolated.

1971/72 North America

When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock terminals 1, 2, 3 and 5 are isolated.

1972/73

With the key inserted and turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

1972/73 North America

When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) terminals 4 or 2 and 5 (white/green) are connected together and terminals 4 or 2 and 6 (slate or grey) are connected together.
When turned to the 2nd position (ignition) terminals 4 or 2, 5 and 3 (white) are connected together, and terminal 6 is isolated.
When turned to the 3nd position (start) terminals 4 or 2, 3 and 1 (white/red) are connected together and terminals 5 and 6 are isolated.
With the key turned fully left or out of the lock terminals 1, 3 and 5 are isolated, and terminals 4 or 2 and 6 are connected together.

1973/74

With the key inserted and turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

1973/74 North America

My wiring diagrams do not show terminal numbers for this lock.
When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire, its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) the brown (12v), white/green (accessories) and slate or grey (anti-runon valve) wires should be connected together.
When turned to the 2nd position (ignition) the brown, white/green and white (ignition) wires should be connected together and the slate or grey wire should be isolated.
When turned to the 3nd position (start) the brown, white and white/red (starter) wires should be connected together and the white/green and slate or grey wires should be isolated.
With the key turned fully left or out of the lock the white, white/green and white/red wires should be isolated and the brown and slate or grey wires should be connected together.

1974 1/2 to 76

With the key inserted and turned to the first position (accessories) terminals 2 (brown) and 5 (white/green) are connected together.
When turned to the 2nd position (ignition) terminals 2, 5 and 3 (white) are connected together.
When turned to the 3nd position (start) terminals 2, 3 and 1 (white/red) are connected together and terminal 5 is isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

1974 1/2 on North America

My wiring diagrams do not show terminal numbers for this lock.
When the key is in the lock in any position there is a connection between the body of the lock (ground) and the purple/pink wire, its terminal is on a different section of the lock to the remainder.
With the key turned to the first position (accessories) the brown (12v), white/green (accessories) and slate or grey (anti-runon valve) wires should be connected together.
When turned to the 2nd position (ignition) the brown, white/green and white (ignition) wires should be connected together and the slate or grey wire should be isolated.
When turned to the 3nd position (start) the brown, white and white/red (starter) wires should be connected together and the white/green and slate or grey wires should be isolated.
With the key turned fully left or out of the lock the white, white/green and white/red wires should be isolated and the brown and slate or grey wires should be connected together.

1977 on

My wiring diagrams do not show terminal numbers for this lock.
With the key inserted and turned to the first position (accessories) the brown (12v) and white/green (accessories) wires should be connected together.
When turned to the 2nd position (ignition) the brown, white/green and white (ignition) wires should be connected together.
When turned to the 3nd position (start) the brown, white and white/red (starter) wires should be connected together and the white/green wire should be isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.

V8

My wiring diagrams do not show terminal numbers for this lock.
With the key inserted and turned to the first position (accessories) the brown (12v) and white/green (accessories) wires should be connected together.
When turned to the 2nd position (ignition) the brown, white/green and white (ignition) wires should be connected together.
When turned to the 3nd position (start) the brown, white and white/red (starter) wires should be connected together and the white/green wire should be isolated.
With the key turned fully left or out of the lock all of the terminals are isolated.