1992 defender

[BillyS]

Picked up my new (To me) defender 90 last week. All was fine, I took the dash off to put some sound insulation in and replaced the dash. All was fine but today after I fitted some carpet I thought I’d take it for a spin to see if the carpet had reduced sound in the cab. But when started the headlights and wipers were on regardless of the stalks‘ positions and when the blower is on max smoke started coming from behind the speedo. To add to all of this when I turned the ignition off and removed the key the engine was still running and won’t switch off with the ignition, but will start. 
 

Took the speedo out just now end seen that the earth wire has melted.

Only thing I have ‘done’ is added some insulation to the hole that lies underneath the passenger side vent where a couple of wires were. 
 

Any advice appreciated, absolutely gutted my first defender not even had it a week! 

[Wowa]

I grounded a live after fitting stereo few years back. Dreaded insulation smoke billowed up from behind dash. The damage was extensive and needed a new loom. Autosparks sorted me out.

[FridgeFreezer]

Land Rover don't fuse the main power feed (large brown wires) going from the starter/alternator into the dashboard so a short back there can set fire to the whole loom - ask @Hybrid_From_Hell how we know that one a bad earth elsewhere can end up with the starter trying to earth itself up the speedo cable and through the dash earth wires which is also unhelpful.

I added 2x 20A fuses on the feed on mine, you could just as easily add a single 40A MIDI-fuse or similar - I used a 4-way bussed fusebox as I was adding fans at the same time - the 2 feeds into the bulkhead loom are on the left, the red wire picks up off the starter B+ terminal.

 

[smallfry]

Must have pinched a wire or punctured with a screw putting the dash back.