I have a 1997 V70 that I have had from new and I'm pretty sure that the heater/air con fan isn't as powerful as it used to be. Does the power from the fan fade? is there anything I can do to restore it? Or do i need to just replace it.
If its a deterioration in the air flow then check that the trunking to the various vents hasn't become displaced. If the deterioration is in temperature required ie cooling then the ac system maybe needs servicing.