Hey...I see a bump!

Ok.. let me get this straight. By manually applying vacuum...you did get air blowing from the various vents etc?

The only electrical lines that I can think of that would go to the selector switch would be for backlighting. I would not expect the wores to become warm or hot during normal operation. The function of air diverting is vacuum only, not electric.

If I'm reading the book correctly, this should be the way vacuum is distributed in each position: (from a 95 manual)

MAX ---> Green, white, blue, orange
A/C ---> Green, white
BI LEVEL ---> Green
VENT ---> Green, white
FLOOR ---> Blue
FLOOR/WINDSHIELD ---> none
DEFROST ---> White

Looks like only your C scenario matches the book. Maybe retest before considering a replacement. If necessary, I still have the one pictured above from a 93 SE.

The vacuum lines seems like they are not the same for a 93... Either that, or i was giving you wrong data... Either way, it does not seem that I have a problem for correct placement of the air. I can get air where I want it it seems. After I took out the wood panel, and clearly tested it, the front vents do switch on and the floor vents switch on when I want them to. (bi-level is still undetermined as there is very little air that comes out of the front panel). However, the amount of air flow is very small.

So... These are the options that I believe could be causing this.

a) Doors aren't moving enough for the front vents. Possibly due to too low vacuum or stuck door. (I don't know how this works, and i'm guessing this is behind the dash so it must be a pain to get to)

b) Crimped line AFTER the selector switch. Basically a problem of low vacuum to a door again. I see a connector that basically attaches all the vacuum lines together right behind the radio. I can't get to it easily to check that it is working properly, but there does not seem to be any leaks.

c) Clogged heater core. Someone mentioned this may be the culprit, I gave it a quick hose but there seems to be some crud stuck to the grill that is mounted in the heater core on the firewall side (I believe this leads to the cabin...)

Would a clogged heater core have anything to do with low air flow? I am not even using the heater setting.

Not a clogged heater core but rather a blocked evap core. A certain percentage of air passes through the heater core depending on the temp select setting. 0% for full cold to 100% for full hot. All of the air passes through the evap core all of the time though. You can inspect for a blocked evap core by removing the blower motor resistor assembly under the hood. Here'* what you may find:

Pine needles, leaves, etc


Varmint nests


Mold:


These are not the only causes for restricted air flow, just three that I've come across when I had a camera handy. If you are confident that your cleaning efforts described above thoroughly cleaned the evap core then I can only think of one other problem. You have a moderate to large crack, hole or breach of the climate control "box" and air volume is being lost dehind the dash. You can inspect the heater core door first. Get a hand up there and feel for blowing air where there shouldn't be any.

Success! Well mostly... Yes, I checked the evaporator core again (this time I actually knew what it was) and there was quite a bit of brown crud on the grills. I then proceeded to spray a can of brake clean and get a brush and scrubbed it. I hosed it down (got a little water on my front carpets) and waited. There was much more airflow this time. The defrost and floor vents are very powerful, except the bivalve switch does not work (only comes out defrost and floor). The dash only switch also does not work fully 100%, some air "leaks" out the floor. But nevertheless, airflow went from maybe 10% of the original factory standard to probably 70 - 80%, a huge improvement.

I think I'm satisfied enough. I could go on forever trying to check the vacuum stuff, playing with the swithces... But I'm just going to take it to the shop now and see if they can charge it with some freon.

Thanks for your help guys!

Nice job and troubleshooting techniques.

There will always be some airflow to the floor and windshield vents by design of the system. I'd guess about 10% would be split between floor and windshield if dash vents were selected.