I have a 2006 9-5 2.3T, when I turn the fan on high for A/C or heat it doesn't blow hard. I can feel a little cold air coming out for A/C, and a little heat when on heat mode, but doesn't blow hard. Is this a compressor problem?
Fortunately it doesn't sound like a compressor rather a blower problem, a lot cheaper and easier.
It could be the switch (not sure what type is fitted to yours) or the blower itself. A blower problem can often be fixed with just new electrical brushes. The blower is under your wipers, have a listen to what its doing. Search here for the fix if needed.