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A/C not blowing from center dash

Tiny
NOBLEGENCON
  • MEMBER
  • 2011 CHEVROLET EXPRESS
  • AUTOMATIC
  • 70,000 MILES
I tried to reset actuators by disconnecting battery for 1 minute you know the routine. Then I just changed the actuator above the passengers feet. I am thinking that is the blend door. Didn't help. I think there is an auxiliary door actuator that directs the air flow from defrost to floor to mid dash. But I am guessing.
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Tuesday, June 30th, 2020 AT 7:34 AM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

Air flow directions is controlled by what is called a mode door. On this vehicle, the mode doors and other HVAC controls are actuated by vacuum provided by a vacuum pump. So, what I need to know is can you change air flow in any direction? There are two mode door actuators, an upper and lower. I attached a pic and circled numbers 1 and 2. One is the upper mode and 2 is the lower. The interesting thing is for you to get air flow via the vents, they both need to work.

So, first, simply check under the dash and make sure the vacuum hoses going to them are attached and not damaged.

Let me know what you find.

Joe
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Tuesday, June 30th, 2020 AT 10:27 PM
Tiny
NOBLEGENCON
  • MEMBER
  • 9 POSTS
Thanks Joe. I did find one un hooked vacuum line (may have been when I was dismantling) and plugged that in and it made no change. The van is a 2011 but only has 70,000 miles I am guessing the vacuum line from the engine being fine but I am going to trace that today. I also went ahead and ordered the control module on the dash. Do you have the schematics of the vacuum supply line?
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Wednesday, July 1st, 2020 AT 2:20 AM
Tiny
NOBLEGENCON
  • MEMBER
  • 9 POSTS
No, I cannot change flow in any direction. Some symptoms where sometimes no cold air. Then after a few minutes even though the knob was on max it would get cold. I knew that was because the blend door had delay. Then I had low flow out of dash air flow and then delayed from say feet flow to dash.
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Wednesday, July 1st, 2020 AT 2:24 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

I have a few schematics, but I need to know the engine size in the vehicle. I'm reading through HVAC information and it's getting a bit confusing because they seem to have offered or made these with two different designs. I know for sure the diesel engines would require the vacuum pump.

Let me know.
Joe
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Wednesday, July 1st, 2020 AT 9:36 PM
Tiny
NOBLEGENCON
  • MEMBER
  • 9 POSTS
I fixed the trouble yesterday. Sadly it was caused by the vacuum line from the intake that was routed over the exhaust manifold from the last guy in there. Dealership mechanic. I had plugs and wires replaced. Melted the side of the line. Thank you very much. What do I owe you?
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Thursday, July 2nd, 2020 AT 2:04 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
First, you are very welcome, and I'm glad to hear you found the issue. And you owe me absolutely nothing. LOL I'm just glad we were able to get to the bottom of the problem. Honestly, your thank you means more than anything else. It's rewarding to be able to help good people.

Take care of yourself and please feel free to come back any time you need help with something.

Joe
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Thursday, July 2nd, 2020 AT 7:38 PM
Tiny
NOBLEGENCON
  • MEMBER
  • 9 POSTS
I am 57 I try to help people too. Have a great Summer.
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Friday, July 3rd, 2020 AT 4:30 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
I'm 56, so right behind you. LOL

You have a great summer as well and feel free to come back any time.

Joe
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Friday, July 3rd, 2020 AT 10:53 PM
Tiny
NOBLEGENCON
  • MEMBER
  • 9 POSTS
Hello, I am rebuilding a 1992 Ford l8000 I have a Delco Eemy high output hd alternator It has three studs with nuts for the wiring. It also has the two prong but I think it is not used. It has an external voltage regulator. When I was dissembling I was trying to take pictures of everything. Now I know where the bat wire goes and from my pic it looks like the other two wire were on the same post. Would you happen to know how it gets wired?"
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Saturday, July 4th, 2020 AT 1:04 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

I don't have schematics for that one. What to do is repost that question under a new thread. Someone will likely have what you need.

Joe
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Saturday, July 4th, 2020 AT 9:59 PM

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