After the brushes went on my '99, I now have a spare set in stock sitting unused in my workbench drawer. The '05 fan still works great at 388,000 km. The blower motor is designed for easy replacement of the brushes.
Is there a write up on how to replace the brushes on the blower motor?I keep these permanently book marked on EBAY used them before and they work perfect.
The fault search shows 0 error codes.The popping sound is likely to be the blend, recirc and distribution flaps returning to their default 'off' positions (which can be pre-set by the user). They are moved by stepper motors hence the multiple sounds as they move the flaps by cranks and pushrods.
As regards the fan, the first step would be to run the fault search by (with engine running) pressing AUTO and OFF simultaneously.
If it shows code 20 its the fan. Its a bugger to get to, but try applying 12 volts to the fan motor direct, and check all the connectors. The motor may need new brushes. Often on the 9-5 its the fan speed controller which has failed. This is hidden above the driver's right toes on the side of the heater box, behind the kick panel. Sometimes they fail completely, sometimes various other symptoms. Interestingly there's no fault code shown for this.
If the controller has failed, some prefer to splice a replacement onto the existing wires, in the footwell, rather than trying to extract and replace the full loom.
The controller is identical for models later than yours i.e. the 2006 - on models. Using an earlier one is obviously more of a risk. Although the loom changed from 2006, the 5 wires are the same colour, hence changing just the electronic lump as an option. The part number difference is due purely to the different loom. Yours has the longer loom.