AC control unit.
Thread Starter
Cruising
Joined: Apr 2014
Posts: 12
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AC control unit.
Hey guys anyone know what jcould cause the AC to come on after starting the car blow thru the vents for a Minit or two then switch to the defrost vent on the dash. This started after I replaced my heater core. It's a digital AC controller with the outside temp on it. it's a94 Lt-1
Last edited by Estevenson; Apr 24, 2014 at 04:02 PM.
Instructor
Joined: Jun 2009
Posts: 109
Likes: 6
From: Scottsdale AZ
Hey guys anyone know what jcould cause the AC to come on after starting the car blow thru the vents for a Minit or two then switch to the defrost vent on the dash. This started after I replaced my heater core. It's a digital AC controller with the outside temp on it. it's a94 Lt-1
There are many, many threads on the Forum which address this exact problem. It is common to late C4's with the automatic digital A/C control unit. Although the fix to the problem is simple, removing the A/C control unit from under the dash (over the accelerator pedal) is a task for one with a flexible body. Once removed, the culprit is the small plastic nipples that is on the control unit which the vacuum harness connector plugs into. These nipples on the later C4's were made of very soft flexible plastic, The nipples collapse when vacuum is applied, restricting the airflow to the valves that open and close the damper doors directing your A/C air flow. This is very well documented here on the forum with detailed instructions and photo's. Just do a search and you will be surprised at the results.
My 96 has the same problem, I need to find a flexible body to help remove the control unit.
Sledge_78
Thread Starter
Cruising
Joined: Apr 2014
Posts: 12
Likes: 0
Estevenson,
There are many, many threads on the Forum which address this exact problem. It is common to late C4's with the automatic digital A/C control unit. Although the fix to the problem is simple, removing the A/C control unit from under the dash (over the accelerator pedal) is a task for one with a flexible body. Once removed, the culprit is the small plastic nipples that is on the control unit which the vacuum harness connector plugs into. These nipples on the later C4's were made of very soft flexible plastic, The nipples collapse when vacuum is applied, restricting the airflow to the valves that open and close the damper doors directing your A/C air flow. This is very well documented here on the forum with detailed instructions and photo's. Just do a search and you will be surprised at the results.
My 96 has the same problem, I need to find a flexible body to help remove the control unit.
Sledge_78
There are many, many threads on the Forum which address this exact problem. It is common to late C4's with the automatic digital A/C control unit. Although the fix to the problem is simple, removing the A/C control unit from under the dash (over the accelerator pedal) is a task for one with a flexible body. Once removed, the culprit is the small plastic nipples that is on the control unit which the vacuum harness connector plugs into. These nipples on the later C4's were made of very soft flexible plastic, The nipples collapse when vacuum is applied, restricting the airflow to the valves that open and close the damper doors directing your A/C air flow. This is very well documented here on the forum with detailed instructions and photo's. Just do a search and you will be surprised at the results.
My 96 has the same problem, I need to find a flexible body to help remove the control unit.
Sledge_78
AC control Unit?
