A.C. Problem?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by sting, Mar 12, 2001.

  1. sting

    sting Registered Member

    Aug 14, 2000
    Likes Received:
    1.Should the ac compressor come on when it is in the VENT position ?
    2.Should air blow out of the lower center vent,the one above transfer case shifter, when the ac is off
    and your moving down the freeway....
    3.If not ,how do i fix this...
    4.Does it help to add an electric fan to the cooling system I have a new four core but was wandering
    if this would be money well spent and if it will help ac system will cool better in the summer....
    I live inTexas ....Thanks MONEY PIT
  2. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Dec 16, 2000
    Likes Received:
    Sioux City, IA, USA
    How can you tell its comming on? A slight amount of air may come out of your vents because the fan acutally runs all the time as part of some ventalation system. You could have a bad switch, unplug the motor and see if it still happens. If this isnt the problem them you may have some kinda wierd air leak but its probably just a switch. There are also some tiny little vacuum lines that come off your control and run to a box under the glove compartment that control the direction of air flow. More than likely that will need some adjustment to get the flow going where its supposed to. I've also heard that the factory actually does an all around better job at cooling than an electric or flex fan.
  3. Pugsley

    Pugsley 1/2 ton status

    Jan 16, 2001
    Likes Received:
    Tucson, Arizona
    Far as the vent goes, I have no idea. But somewhere down the line, GM rigged it so the compressors cycle randomly - I'm not sure why or what year, but my 78 never did it and the 85 does.
  4. Ditchdigger

    Ditchdigger Registered Member

    Mar 11, 2001
    Likes Received:
    The Great Midwest
    I agree with Pugsley on the cycling
    It is because of low pressure in the system
    whether theres a leak or your system needs
    to be charged it turns on and off to circulate oil
    so pump doesn't lock-up my 91 Firebird did
    that (kickin on and off) but airconditioning wasn't that
    important to me I like the window down besides it robs
    horsepower and gas so I disconnected the clutch
    harness on the pump but I know I could of fixed it
    by charging Freon and oil!
    as for the continuos air flow you might want to check
    duct flapper and may need to be adjusted or could be low engine vacuum my Blazer(84) did the same thing
    until I fixed leaking intake and adjusted the flapper!
    but it still seems to let a little air through which is ok!
    Glad to help!

    If it ain't intimidating / It ain't a Chevy!

Share This Page