l have removed the glove box but still can not see the resistor pack. l have a renault laguna 1.8 petrol 1997 with air con. l have bought a replacement but can not fit it without some expert help in finding the old one. currently the control switch only works on number 4. thanks tom

Should be mounted on the blower motor as below;

http://img98.echo.cx/img98/782/laguna4gn.jpg

either accessed from behind the glove box or under the dashboard.

If you have managed to find the heater fan then you should be able to find the resistor pack. The resistors have to be placed in the airflow to keep them cool & prevent them from burning out. You should consider spending £15 on a haynes manual for your car though as it will help you out a lot!

Take out the glove box and you will see the resistor held in the heater box with 2 (i think) screws.
This is a very common fault.