200tdi ignition switch melted cables

After dying completely on me on the motorway I've finally got round to having a look at the back of the ignition switch only to find the live wire had melted onto the brown/red wire. Apart from changing the brown live wire stretch and patching the red/black, how do I go about fixing this so it doesn't happen again?
Thanks

Have you got a relay for the heater plugs? My NAD didn't so the full load was carried by the switch contacts.
I had similar melted wires on mine, spotted during the rebuild 14 yrs ago so I used those wires to trigger a relay instead, mounted it behind the fuse panel.
You may need a new ign switch too but they are quite cheap.

Clean all earth and wiring connections and replace any discoloured wiring as best you can.

Life's a beeatch sometimes. Mine set alight (actually I set it alight almost accidentally) and burned wiring out, but in the end it helped 'cos so much of the rest of the wiring is pretty duff, so we have an on-going plan of attack to change bits of wiring as and when we have access.