A/C Air Flow Keeps Moving
Thread Starter
Intermediate
Joined: May 2004
Posts: 47
Likes: 2
From: atlanta ga
A/C Air Flow Keeps Moving
I have a 98 C5 w/88,000 miles. When I turn on the AC, the air blows out of the defroster vent initially but keeps changing vents. It will then blow out of the upper and lower vents briefly and then back to defrost over and over. It doesn't matter what the settings are. I tried disconnecting the battery to reset the actuator with no luck. I'm unable to check the codes. Is this a vacuum problem? An actuator problem? The control unit?
Burning Brakes
Joined: Jun 2010
Posts: 1,014
Likes: 5
From: Rockwall TX
I know someone on here can give you a lot better directions then myself. But, this sounds like a vacuum issue. There is a line that comes from the back of the engine, travels down through the area under the battery, and I believe to an air canister, and into the passenger foot area. You should probably check that line first by going under the dash on the passenger side. Remove the lower panel, and you will see an electronic selonoid with all of the vacuum lines, check the single line to the selonoid first. I really don't want to give you bad advice so I hope someone else will step in to give your better directions. That will at least get you looking in the general area.
Thread Starter
Intermediate
Joined: May 2004
Posts: 47
Likes: 2
From: atlanta ga
Thread Starter
Intermediate
Joined: May 2004
Posts: 47
Likes: 2
From: atlanta ga
I know someone on here can give you a lot better directions then myself. But, this sounds like a vacuum issue. There is a line that comes from the back of the engine, travels down through the area under the battery, and I believe to an air canister, and into the passenger foot area. You should probably check that line first by going under the dash on the passenger side. Remove the lower panel, and you will see an electronic selonoid with all of the vacuum lines, check the single line to the selonoid first. I really don't want to give you bad advice so I hope someone else will step in to give your better directions. That will at least get you looking in the general area.
Burning Brakes
Joined: Jun 2010
Posts: 1,014
Likes: 5
From: Rockwall TX
When you run the car can you feel the vacuum on the main line? The usual break on the line is in the engine bay area. The line runs from the back of the manifold down (I believe) by the bottom of the battery area , but I would make sure that the vacuum is holding on the main line, and if not you can follow the line back to the engine. I know when I pulled my line (under the dash), even after sitting for a while, I could hear the vacuum air releasing when I pulled the line off the selonoid. Pull the line off and see if you have vacuum.
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