HVAC hose destination

Tiny
PRAIRIE02
  • MEMBER
  • 1994 CHEVROLET VAN
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 118,000 MILES
Van has a black ball (like toilet float) under hood that should have a vacuum hose attached. I think it controls heater, maybe cruise control, other stuff. I have no heat but plenty air for A/C. WI needs heat ha ha. I think it may go to a control module that may be located on firewall by driver's fender/bumper but can not find anything in Haynes or Chiltons. What do I look for and where? Do you know if the hose length is pre-made and what it would be called or do I have to locate module and measure? I am a seventy one year old female diy'er, but realize I may have to take to mechanic as it may have to go on a lift. Any and all help is appreciated.
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Thursday, November 29th, 2018 AT 8:59 AM

3 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning,

That is a vacuum chamber for the mode doors inside the van. It should have manifold vacuum from the engine to it and then a line from the tank to the control head inside the van.

Can you verify that?

Roy
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Thursday, November 29th, 2018 AT 9:07 AM
Tiny
PRAIRIE02
  • MEMBER
I do believe it should be connected to the mode doors inside. I will have to check if one hose goes there (top one maybe). But where would the hose that should be attached to bottom of reservoir go to? Where do I look? Would a hose connect to the manifold somehow? I will take this reply and picture when I go to a mechanic. Where inside do I look for the control head? Dash? Thanks again, this is very helpful as it is unseasonably cold here in WI, snowed last night and no heat in van.
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Thursday, November 29th, 2018 AT 9:18 AM
Tiny
ASEMASTER6371
  • EXPERT
One hose comes from the engine and the other goes to the control head. The mechanic will have to remove the control head to verify vacuum.

Look around as the hose should be there.

Roy
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Thursday, November 29th, 2018 AT 9:37 AM

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