Who is they?

My guess is that whether or not the car has a/c is irrelevant as far as what is wrong. The resistor pack may be different between a/c and non a/c equiped cars, but it will be seperate from the blower motor. You need to find out where it is located. Some cars it's easy, others require half the dash to be removed. Have a look on ebay for 'Picasso blower resistor' to see what they look like. They are not expensive, although the labour if you can't DIY, could be high.