Very Little Air Blowing Out Of Vents 2000 Yukon Denali

[Timbers]

Hello everyone. My 99 Yukon has little to no air moving out of the vents for heat or for cold. I'm thinking its either a severely clogged evaporator or maybe something wrong with my HVAC unit? Heres what I found:

Evaporator coil was covered with leaves and debris, vacuumed it and even sprayed it with cleaner and hosed it out with a garden hose. Doing this made things worse, now theres barely any air moving. I did not bend the fins....

Switching between floor, vents, and defroster does seem to work as I can hear the doors moving and feel air switching between all three.

Fan screams and works at all speeds. Ran the fan outside of the air box and it spins at the proper speeds, extremely fast at high speed.

I noticed thin black pieces of foam gasket material hanging out of the floor vents on each side of the console. I pulled them out. I'm guessing these might be pieces of the doors that are in the HVAC unit?

Since it got worse when I cleaned my evaporator, I'm thinking maybe its that. Does anyone know of a way to get at the other side of the evaporator? Can I drop the housing on the heater core and do any further cleaning? Can I take a brush with long hard bristles and poke it through the fins in an attempt to dislodge more gunk?

Or do you think my HVAC unit doors are preventing the air from moving up into the ductwork? Thanks!

 

[east302]

Feel around the bottom of the ducts and see if you can feel an air leak - particularly at the center floor vent. If the evaporator is not clogged, the air will be going somewhere.

If you don’t find anything, try cleaning the coil again with a self-rinsing aerosol/foaming coil cleaner. A big box store will have it.

You cannot access the downstream side of the coil without pulling the dash. It may have just been clogged more than you thought and pushed more debris into the fins somehow. A few passes with the cleaner may help dissolve whatever is in there.

If you can get a good look with a flashlight, see if the fins are all smashed in.



The black rubber in the floor vent is probably the lower air door. They tend to deteriorate on the edges and cause an air leak at the floor:




Sent from my iPhone using Tapatalk

 

[Timbers]

Feel around the bottom of the ducts and see if you can feel an air leak - particularly at the center floor vent. If the evaporator is not clogged, the air will be going somewhere.

If you don’t find anything, try cleaning the coil again with a self-rinsing aerosol/foaming coil cleaner. A big box store will have it.

You cannot access the downstream side of the coil without pulling the dash. It may have just been clogged more than you thought and pushed more debris into the fins somehow. A few passes with the cleaner may help dissolve whatever is in there.

If you can get a good look with a flashlight, see if the fins are all smashed in.



The black rubber in the floor vent is probably the lower air door. They tend to deteriorate on the edges and cause an air leak at the floor:




Sent from my iPhone using Tapatalk

Thank you I will check. Nice pictures, you are right thats the gasket material I found sticking out of the floor vents. I'll try cleaning it again.