I've had a 55 reg Scenic for nearly a couple of years now. Since I had it speed 2 on the fan never worked and I just put up with it. A month or so ago speed 4 stopped working too, so I have only speeds 1 and 3 left.
Last week me and my housemate looked at what's inside. He took the trim around the dashboard display off but it was me who had to get the resistor pack out, as I have small hands and matchstick arms. Very interesting having to unscrew the thing while my hands were totally hidden I must say, having to feel around and do the whole thing by touch, but eventually got the loom and pack a little way out. The loom was partially melted and the pins on the resistor pack didn't look good either. It is the original 5-pin design.
I couldn't get the resistor pack out completely as there wasn't enough red and black cable visible. Me tugging it didn't bring any extra cable through, but I wasn't pulling very hard; I think when my housemate next tries it he'll have the courage to pull harder...
I've ordered a replacement resistor pack for just £43 from here: http://www.eurocarcare.net/heater-co...701207876.html
and this is the new 7-pin version. One extra pin is B2 which is connected to B1; both link to the red cable to the fan. The other extra pin is A5 which is connected to A4, which links to the black cable and to one end of the resistor pack. This may help those who are wondering where to splice in extra cables.
As for the loom, my housemate suggests just doing away with it altogether and using individual spade connectors soldered onto the end of the wires in place. Not sure how reliable that would be, but would save me £39.
Unfortunately he's away this weekend, so I don't know when we'll be able to fit it.