Had same on mine, blower was filthy and contained remnants of cobnuts from the mice living in the bonnet insulation.
BTW I found no need to remove glovebox, it can all be done with that in place. Once removed, I pulled the impeller off the motor and gave the whole thing a good clean, then a non-sticky oil to the motor. From looking at the design, it seems to draw cooling air for the motor in from the air plenum, so naturally pulls in all the dust and dirt to the motor area. As an aside, I found that as a temp fix (before I took it all apart) was to weave the vehicle left and right, or to switch the cc on and off. Seemed to temporarily stop the chirping, but then again it wasn’t a big fix to do it properly. You may also find bits of the filter gauze in there from the scuttle intake....