Hi:

For a while now my air con has been worsening. First of all their was a whirrring noise in the system - sounded like it was where I presume the air con unit is housed (passenger side under air bag area). This would be ok for a bit then sound again on and off for around 6 months. Of late however no.4 on the dial will only work and as it's the stongest it can make an awful unnatural din of whirring as though the car is about to take off (joking a bit). This lack of control on heating and cooling especially in the upcoming months is really annoying.

Would this be an easy fix or should I reluctantly take it to an auto electrician and stump up the cash. I have a rear windscreen wiper fault and a relay light fault inside the motor that he/she could review at the same time.

Thanks in advance. Any knowledge imparted I would be grateful of as I'm a bit of a dunce when it comes to motor vehicles.

Firstly I reckon your heater matrix or fan motor have broken down and as to the wiper fault would I be right in saying that it works ok when pushing the wash button but stops half way when on normal wipe?
In that case I'd get the wires from the roof to the boot in the black rubber conduit checked for breaks as it's a common area for wires snapping off due to dried out insulation.
An auto electrician would be a very good idea as they would be able to sort that out very quickly.