filter not an option on the vans
the video linked below shows what we are dealing with
rather than pull the entire housing off, removing the fan and working through that hole is easy-
removing the resistor block gives a small cavity- but perfect for inspection
I have a small dirt devil which has a small diameter hose that can get in there
also check for blocked drain/weep hole- easy for us in AZ on a humid day, water about pours out
but I have had issues with wasps so worth checking
( my house ac condensate line gets blocked by wasps regularly- I use a shop vac to suck it all through)
some harley riders get the tranny vent tube blocked by wasps, which will cause tranny lube to leak out the clutch cable at the adjuster
mike