99 Tahoe - A/C Air Flow is weak at vents

Discussion in 'The Choo-Choo shop' started by Smartin, Aug 8, 2010.

  1. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Everything seems to be working properly. Blower is running at high speed, evap core is clear, and the doors are all working the way they are supposed to. I just don't have a lot of air flow through the vents. All of the 2003-2008 Chevy trucks I've driven will blow my hat off. This one seems to be only about half the flow of the newer ones.

    Is there a higher flow/efficiency blower available?

    Or should I just sell this thing and find another one that doesn't have 4000 problems?:rolleyes:
  2. cstanley-gs

    cstanley-gs Silver Mist

    Do you hear a difference in the blower when you switch from AC to max AC (recirc)?
  3. gsgns4me

    gsgns4me Well-Known Member

    I believe that model MAY have a cabin filter. Sounds like it's time to replace it.
  4. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    No cabin filter that I can find...some say it has one (the interwebz), and the guy at the oil change place says no.

    Curtis, I don't hear a difference in blower speed when I switch to recirc/max AC, but the recirc door works. Even at regular high speed, it still is weak though.
  5. gsgns4me

    gsgns4me Well-Known Member

    Underneath the right "hush-panel, a narrow "L" shaped piece of plastic on the heater housing. One 9/32" screw in lower part of "L", maybe another up top. At least from what I can remember. Been too many years.

    NAPA part #SFI 224805
  6. cstanley-gs

    cstanley-gs Silver Mist

    The reason why I ask about the recirc door is that I too had very little flow from the vents in my explorer. I could see the actuator moving for the recirc door, but after taking apart half the dash, I found the recirc door had fallen out of place, and had fallen down and was laying across the top of the blower motor. No air could move from the blower!

    Basically the arm the swings the door was working, but the door was no longer in place to be moved.

    You should hear a increase in noise when on max ac as that closes outside air and lets the blower suck inside air. Because the blower is open to the inside now its louder.

    The replacement part is $49, but ford wants 7hrs labor to put it in, the complete dash has to be moved from the firewall. I managed to get the door out, and have much better flow now. Ill replace the duct myself one of these days.
  7. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    When I pull the bottom of the heater box off and drop the heater core down, I can see the outgoing side of the evaporator core. When I pull the blower motor, I can see the other side of it. There is no cabin filter that I can find....unless it's downstream of the heater box.
  8. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Curtis, the recirc door is in the correct position when engaged. Everything appears to be working, I just don't get much air coming out of the vents.
  9. gsgns4me

    gsgns4me Well-Known Member

    Please take into consideration that I'm working off a bad memory, but illustration part #20 is the cover I remember allowing access to the cabin filter.

  10. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    That diagram doesn't look familiar. My blower motor sits vertical, and the heater core is at a 45* angle. The entire bottom of the box unscrews with 5 or 6 7/32 screws, and the heater core is exposed.

    The 99 Tahoe is still the "old" body style, and from what I have read, they only used the cabin filters on the 99's with the newer body style.
  11. gsgns4me

    gsgns4me Well-Known Member

    "I see said the blind man":pp
  12. cstanley-gs

    cstanley-gs Silver Mist

    The only other suggestion I can offer is...

    Depending on the location of the recirc door...

    Is it near the glove box?

    In my older explorer, I had some tissues from the glove box get sucked through the grill on the recirc door, and that greatly cut down on air flow...:Dou: took me some time to get them out... I keep tissues in the center console now
  13. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Installed new blower motor resistor and blower motor tonight. No change.

    Time to drive this thing off a cliff....or just put it on craigslist.

    This truck has stumped me with every little problem since day one.
  14. APVGS

    APVGS Ottawa Go Fast Guy!!

    Adam that Tahoe could have an evap filter, not sure if it does for sure but #15-33308 is the Delco part #.
  15. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Tahoe is now dumped off a cliff. Replaced with a 4x4 Yukon. Problem solved.

    Attached Files:

  16. cstanley-gs

    cstanley-gs Silver Mist

    No way LOL you were serious about getting rid of it! :laugh: :shock:
  17. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Yep, it's someone else's problem child now:laugh:

    I've had nothing but issues since I bought that thing, and I thought I could fix them all...but they turned out to be gremlins that I pulled my hair out trying to take care of. The last straw was an interior door handle that broke off in my hand 2 nights ago.
  18. myriviera

    myriviera Well-Known Member

    Sounds kinda dumb but I have heard of someone replacing the blower motor on a 97 Burb and switching the wires and the blower running the wrong way. And yes you can switch the wires and it will still run. Funny thing is not much air moves thru the vents with the blower running backasswards. Switched the wires and low and behold more air thru the vents. Just an idea. Dont know who would have done something real dumb like that.

  19. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    I had the same thought on the way to work this morning:Dou: Never tried it.

    Oh well!!

    I have what I want, now. Working AC, headlights, 4x4, and a towing package.

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