I pulled the trunk carpet yesterday to wash it as I spilled oil on it so while it was out I decided to check the blower fan in the trunk.
I figured if GM thought it was needed I should really get it working, at least for the ignition coil part.
Sounded like it was trying to work but nothing coming from the vents so I pulled the fan and found this:
Put it back together and tired it. Still no air!
So I removed the feed tube (from the fan to the trunk wall). It was full of mice nest as well.
Cleans that out and ran an air line through it, nice and clean now.
Unfortunately I threw the old tubes out (I think) when we moved house so I'm trying to get a new set but at least the fan works now!
Anything I might say is probably worth what you paid for it, so treat it accordingly!