92 Caprice Low Air Output from ALL vents.

I have a weird problem with a 92 Caprice. I am getting low air volume from ALL vent positions (ac/max/heat etc). The temp lever works fine.
I am also getting frosting on the A/C evaporator which indicates to me
that I am not getting airflow on the evaporator itself.
The blower motor is fine and is blowing a mile a minute.
I had the the Air box apart (no easy chore!) and it seems like the evaporator is clean.
For the life of me I can't figure out what is wrong but I am guessing that the "main door" is somehow blocking the flow of air from the motor to the rest of the system because like I said, I get low output from all outlets depending upon where the lever is set.
Anybody have any ideas?
I would hate to have to remove the blower box again because like I said it is a royal PITA.
I was thinking of maybe flushing out the box by squirting water into the drain hole and then backing the car up on ramps to let it drain out.
I have the FSM but it is not really helpful for this.
Any ideas?
All vacc hoses appear to be connected and I don't hear any leaking but I suspect whatever the first door/object the air passes through on it's way from the blower to the various vents is not open all the way.
Tia.
Simon
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your heater core and ac evaporator are plugged with debris this is an common problem after car is 5-6 years old . They need to be blown out .
Rey
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On Wed, 06 Jul 2005 17:35:23 -0500, Reynaud wrote:

That's what I thought, but the heater core is a couple of months old and when I had the box open I looked at the evaporator and it looked fine. The foam had corroded (looks like an air conditioner filter) so I removed all that, but it's still the same.
Any way to clean that out without removing the bottom cover again? I've seen the foam stuff you can squirt in there through the drip outlet which made me wonder if I could flush it from the same outlet with a hose?
I'm also wondering if it's getting any air to the blower from either outside or inside the car (MaxAir) and trying to see what's common between the two. No air and no matter how fast the blower is turning it won't produce anything out the vents.
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What I did was add a second vacuum resivoir to the system, the added capacity seemed to solve problem. Squirt a blast of dishwashing detergent down the cowl now and than, when wet, it loosens dirt [ leaves are tough ] Another way is to remove heater blower motor, and pour soapy water [ pour slowly, watch rugs ! ] into bottom of system
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On Thu, 07 Jul 2005 16:17:48 -0400, 451CTDS wrote:

I think that is the path I am going to take. I'm going to see if I can locate another vacuum tank and also go with the soapy water trick.
I remember seeing some foaming spray to remove musty smell etc from these things and according to the instructions you squirt it into the drain hole and flush. No need to open the system up, although I would remove the blower motor and put a large pan and towels under to collect the water.
I hate like hell to have to remove the lower half of that beast again. I was sore for 3 days the first time :)
Thanks for the information!
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I had similar symptoms on my '88 Z-24 when I bought it. I discovered the evaporator was plugged with this black spongy stuff, almost looked like the blower fan somehow chewed it into little bits and sent it into the evaporator, clogging it up. But it was just PACKED in there--no wonder it wouldn't move any air. IIRC I was able to remove the blower resistor mounted in the box, and I took a powerful shop-vac and duct-taped a 1/2" ID piece of hard plastic hose into the end of the shop-vac hose, and stuck it into the hole in the box and sucked all that stuff out of there, and LUCKILY it worked perfectly after that! (I really didn't want to take the heater box apart). I don't know how similar your heater box is to mine, I probably just lucked out due to the configuration of mine, but I'll bet it's the same problem.
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James Goforth wrote:

I stuck a gareden hose in thru the resister pak hole on my 89 bonni. Works perfect now.
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On Sat, 09 Jul 2005 15:10:42 +0000, Tim Thomson wrote:

You guys are great!!!!!!!
I used a combination of methods and yes, I had all the spongy stuff which turns out to be a fliter, like the ones on home window A/C units.
The stuff was, like you say, packed so tight I didn't even realize that it was there because it looked like it belonged!!!
Car is working great now thanks to the advice from everyone!!
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Check if your vaccuum line is hooked up for changint hte doors if not the door has no vaccuum they all work
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