Vent setting blows out lowers only

Discussion in 'The Big Chill' started by darren fitzgerald, Jan 28, 2019.

  1. darren fitzgerald

    darren fitzgerald 77Century

    Picked up a 76 century and when set to vent it still blowers out the lowers and not the vents. Is this a manual control, vacuum or electrical? Where should I start looking to correct this? Also, the compressor was removed and none of the a/c settings blow. Is that because the compressor is gone and it is needed to complete an electrical loop? Are these two things probably related?

    Thanks for any help!
  2. buick64203

    buick64203 Just plum crazy Staff Member

    If its not blowing out of the dash, that's a vacuum issue. First thing is to check that you actually have vacuum going to the heater controls. The switch on the dash just directs vacuum to the diaphragms. If you have a hand held vacuum pump, you can check the diaphragms individually. Apply vacuum and see if they operate and don't bleed off. That's dependent though on if you can reach them. Chances are if you have good vacuum going in and the switch is operating properly, you have a bad diaphragm somewhere. I think there are 3.

    You can try taking off the passenger side kick panel and seeing if there's one under there like the 70-72 cars. That one should have 2 vacuum lines going to it. Pinch off those lines and see of it blows out of the vents. If it does, you just found your bad diaphragm.
    darren fitzgerald likes this.
  3. Premier 350

    Premier 350 Chris (aka Webby)

    I'm wondering if the vac line isn't off altogether? When I picked up my '69 I only had air from the heater outlets. Found the vac line was off the canister. Refitted it and it's worked ever since.

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