How Do I Know If The Brake Light Switch Needs Replacing?
If you have problems selecting reverse or getting from reverse to neutral or indeed if you notice
none of the brake lights are working, there is a chance you will need to replace the switch.
Not Selecting Reverse
On the 451, most of the reverse issues are clutch software faults, see here.
Why Has It Happened?
The failure of the switch is almost certainly down to 1 of 3 possibilities.
Switch contacts failed.
Switch short circuited due to water ingress.
Switch submerged in water.
The switch box cover has a drain port which can get blocked,
massage this port to see if any water comes out.
If a lot of water comes out, the drain was blocked and the switch could
have been submerged. We all know that water and electrics don't mix.
If a small amount of water came out, you have a leak into the box which isn't that bad.
The wiring can be rectified so any water won't affect the new switch.
If no water came out, the switch probably just died of natural causes.
What Parts Do I Need?