Air flow

Discussion in 'The Big Chill' started by cb3071, Aug 23, 2014.

  1. cb3071

    cb3071 Well-Known Member

    Have a 1971 Skylark and the AC works good....except airflow from the vents is weak. New stock type blower motor installed couple of years ago and converted to 134 . Any ides on how to get more air flow??

    All the ducts are solid and attached tight and the controls work great...low, medium and high all work. Seems like passenger side air flow is weaker than drivers side.

  2. knucklebusted

    knucklebusted Well-Known Member

    Does it sound like the fan is running at full speed but the air just isn't very high flow? If so, is it coming out the front vents only? It might be blowing out the heat and defrost as well. Does it shift from defrost to heat to dash vents OK? It could be vacuum lines if it won't select. You could try closing off the side vents to see if it comes out the center stronger.

    If it is only blowing out the dash vents, you'll want to look under the dash to be sure everything is hooked up and no hoses have come loose.

    Barring that, it could be a clogged evaporator core. Is hot and cold the same flow of air? Check under the hood to be sure the intake area on the passenger side isn't full of leaves or debris.
  3. cb3071

    cb3071 Well-Known Member

    All the above are ok. The air doors are working but the heat and de-ice blow better than from the vents. Have not tried closing the side vents..good idea. It sounds like maybe evaporator core cold be clogged or intake could be gunked up. Are those easy to get to?

    Thanks for the input.
  4. knucklebusted

    knucklebusted Well-Known Member

    If the defrost and heat seem good, I don't think it is the evap core as long as you have it on cold and the AC would be running. That should cause the evap door to be at least partially open.

    Define easy? If the screen or anything you can get to from the screen on the passenger side is where it is, it will be fairly easy if you have a small enough arm and are limber. The evap core is a pain and is in the big fiberglass part that sticks into the engine compartment. Never had one of those apart with the engine still in the car. Lets hope it isn't that one.

    You might try using a vacuum reversed to blow out the core from inside then use a vac to see if you can suck any of it out from the outside top.

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