A common fault on the 450s is the failure of the light stalk.
The failure of the stalk is usually manifested in one or more of the following issues:

• End of stalk getting warm/hot during use
• Dashboard lights not working, or slow to respond
• Main headlights not working, or slow to respond
• Rear lights not working, or slow to respond

This failure is actually regonised by smart and is subject to a VOSA recall.
The recall ID is R/2003/046, please check with your local smart dealership incase you are eligible for a replacement free of charge.

If you are not eligible, or wish to fix the issue yourself this guide will show the simple steps to achieve this.

First, disconnect the battery - Remember to have your radio code to hand!

Now twist the stalk through to the fog light position. When removing the end, you may want to use a plastic bag to catch the spring which pops out!
Now pull the stalk end whilst twisting further. It is a very tough fit, but will pop off.

The stalk end will come off, and you'll be left with the twist connectors.

Ensure you have the small bullet spring which will come out of the hole on the stalk frame.

Pull the switch ring carefully off the frame, you may need to twist it about 5 degrees back in order for it to release.
It will have a soldered wire onto it, so it won't become fully detached.

Now using some contact cleaner, spray onto the contact ring, and onto the spring connectors and wipe using a paper cloth. You will be suprised just how much dirt and tarnish comes off.

Locate the bullet spring back into the stalk.

Firmly press back the lightstalk end. Reconnect the battery and test.