Sand in my HVAC system... please help

[gsxrkid]

Ok so I will preface this with the fact that sometimes I can be a complete idiot, so we can get that right out of the way first.. haha

So lets get to the issue. This weekend I let the girls take my truck out to Olds hill in Glamis and everything was good until the way back. Yep, I'm sure you've figured out where this is going.. buried up to the wheel wells.

After multiple attempts to pull it out with trucks and sand rails and after dump truck sized loads of sand poured over the entire truck we finally got her free. On the way home we noticed something that probably could be expected from that experience. The second we turn on the blower motor for anything whatsoever, a sandstorm erupts inside my truck and all over the leather seats and carpet. The entire system is completely full of sand. I took the shop vac and air compressor the best I could and blew/sucked out the heater vents and anything I could think of to clean out. I can't see anymore sand anywhere inside the engine compartment or anywhere else.. I don't know what else to do..

What do you guys think is the best way to clean it out without just turning on the fan and letting it run and destroy my interior for an hour? Not to mention probably destroying my blower motor in addition.. any suggestions would be greatly appreciated!!

 

[CrashTestDummy]

I'd start by doing this:
1. verify there's absolutely no sand near the HVAC intake that's between the firewall and windshield.
2. remove the blower motor and get a vacuum cleaner as far into the duct work as I can.
3. pop the trim panels off the dash (the center panel also houses the center ducts, so when you remove it, you also pop the vents off. Get a vacuum into as much duct work as possible.

Then depending on how much more sand comes out when I turn the blower on, would determine whether or not I pull out the service manual and start looking at removing other panels.