Strange Electrical Fault. Urgent

[Richie-Van-GTi 71 2 Cars]

set off to take daughter to school this morning, got about 3 miles up the road and smoke was pouring from behind dash, smelt like electrical burning, car was running fine and all gauges etc normal. Pulled over and switched off, got my hand in behind dash and couldnt find any warm wires or blown fuses. My heater hasnt worked for a long time, I assumed it to be the fan itself and wondered if it was the fan shorting somehow. Anyway Ive got the heaterbox out now as I have a replacement. I plugged everything back in but all kind of hanging out to see if any wires smoked etc, nothing but the fans came on full pelt, I tried turning the switch even though it was in the fan off position and the fan just remain on full whack. Ive tried switching the small card over that goes in the bottom of the heaterbox but still the same. Could it be the switch thats gone and caused all these issues? Need as many tests and possibilities as you can all think before I spend hours putting it all back together.

[steve@cornwall 100]

Only thing I can think of is that the tracks on the rheostat controlling fan speed have shorted- would think that this would be traceable just by sniffing the controls! Bit of a shot in the dark but may help

 

Good luck- I hate anything to do with those fans- seem to be permanent live and variable neutral- French weirdness

[Richie-Van-GTi 71 2 Cars]

Thanks, I chexcked and they are bone dry, might have to resistance test them at various positions or something. Failing that Im gonna stick a switch inline with the fans and just have on/off for now

[danpug 1]

My mates 205 has a similar thing. Fan won't switch on or off unless a switch is rigged up and we also smelt electrical burning on a few occasions when the fan was switched on via the switch.

[Richie-Van-GTi 71 2 Cars]

well swapped the heaterbox, put a switch on the fan and no more smoking, damn matrix is leaking now though, its just were the pipes connect so I'll sort that tomorrow now, bit of an ass though trying to get access with fixed buckets and cage with door bars