Can't the H2 A/C be run in the re-circulate mode? That's what I do when I run the A/C in my 85 Toy to avoid sucking lungfulls of dust.
Founding Member of RCRC 4wd Club Scaramento, CA
www.rcrc4x4.com
Pirate4x4.com Vendor & Toyota Truck and 4Runner Talk Forum Moderator