Smoking Hazard switch

After the Suffolk BBQ on saturday I put the car back in the garage. Went back a few hours later and disaster. The Haz lights where flashing and a coil of smoke was rising from the Haz switch (Sierra type). Also the ignition and oil lamps where faintly lit (glowing not alight!)

I have taken it off and the moulding in the Haz switch has blackened and partley melted. Strangely and unfortunately it didn't blow the fuse. Also strangely everything had been working fine beforehand and I have done quite a few miles so I dont know why it would suddenly go.

I have another switch now but before i wire it in the same I have a question:

I wired it in as per the diagrammes that where posted last year and it worked fine. However it has live feed into the switch but is not protected by a relay (forget the flasher relay). So effectively the current for the whole lot is going through the switch. Is this correct (I could not find another diagramme incorporating another relay and it held out for a long time wired this way).

If it should have a protection relay if so where in line do I put it?

or was I just unlucky and the switch developed a fault?

Cheers Chris

Well no response on this one yet so I'll ask another question:

should I put a relay between the switch and the flasher relay and /or a relay between the switch and the indicators

Mine started flashing the ign and dash lights after it had been rained on and it's done it ever since but I've never left them on for any length of time so I don't know about the melting problem Chris. Did you have a good earth on the column switch as it sounds like the problem is resistance somewhere on the way to earth. What fuse rating have you used, you could try a lower one and see if it blows it.