Interesting A/C problem PLEASE HELP
Thread Starter
Safety Car
Joined: Nov 2001
Posts: 3,753
Likes: 191
From: Orange County California
Interesting A/C problem PLEASE HELP
For the last three weeks my light for the A/C button on the climate cotrol blinks and the A/C does not work. Then after 5 - 15 minutes of driving all the sudden it start working flawlessly out of the blue and the light does not blink but is on steady as it should be.
What the heck does this mean and whats the fix??
All help appreciated.
Robert
What the heck does this mean and whats the fix??
All help appreciated.
Robert
Team Owner
Joined: Jan 2002
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From: All that glitters is Gold - Hockey Is CANADA'S game
Cruise-In VI Veteran
Cruise-In VII Veteran
St. Jude Donor '05-'06
There is nothing wrong with you A/C here is what it says in the owners manual, take not of the bold text
A/C: This button turns the air conditioning
compressor off or on under most conditions. The light
on the A/C button will come on when the compressor is
operating in either the automatic or manual mode. The
air conditioning does not operate at temperatures below
approximately 35F to 40F (2C to 4C). The light
on the A/C button will flash if pressed when air
conditioning is not available. The air conditioning cools
and dehumidifies the air coming into the vehicle. The air
conditioning cannot be turned off in DEFROST and
DEFOG, as it helps to remove moisture from the
vehicle. It also helps to keep the windows clear.
compressor off or on under most conditions. The light
on the A/C button will come on when the compressor is
operating in either the automatic or manual mode. The
air conditioning does not operate at temperatures below
approximately 35F to 40F (2C to 4C). The light
on the A/C button will flash if pressed when air
conditioning is not available. The air conditioning cools
and dehumidifies the air coming into the vehicle. The air
conditioning cannot be turned off in DEFROST and
DEFOG, as it helps to remove moisture from the
vehicle. It also helps to keep the windows clear.
Thread Starter
Safety Car
Joined: Nov 2001
Posts: 3,753
Likes: 191
From: Orange County California
I see that hits the nail on the head.
Too bad for me the external temp reading is rarely right. It is very windy in ATL today and it says it is 31 out when its well into the high 40's. Last week it was 70 and it said 42
Also should the a/c work when the defroster is on regardless??
The external reading is always riht after a few minutes of driving so i guess you hit the nail on the head
Too bad for me the external temp reading is rarely right. It is very windy in ATL today and it says it is 31 out when its well into the high 40's. Last week it was 70 and it said 42
Also should the a/c work when the defroster is on regardless??
The external reading is always riht after a few minutes of driving so i guess you hit the nail on the head
Team Owner
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
I started having an almost identical problem last week also.
Same thing.....blinking AC button. My EXT temp was reading 57........outside temp was actually high 60's to low 70's. About 15 minutes into my drive everything started working ok........
Then yesterday it just started blowing warm air.......clutch engages.....but just warm air comes out......more AC button blinking and 57 degree reading again.......
Melting Slicks
Joined: Sep 2003
Posts: 2,669
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From: Florida Gulf Coast
St. Jude Donor '05-'06-'10-'11
Originally Posted by robertpel9
Also should the a/c work when the defroster is on regardless??
Read above Grasshopper........much knowledge to be learned if you read.
Last edited by WolfeBros; Mar 8, 2005 at 02:32 PM.
Team Owner
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
Originally Posted by WolfeBros
Yes the A/C comes on whenever you are in the defrost mode.
Read above Grasshopper........much knowledge to be learned if you read.
Read above Grasshopper........much knowledge to be learned if you read.
Come summertime, I don't want to be driving around for 15 minutes in 100 degree heat with no AC waiting for it to figure out the correct outside temperature........
Thread Starter
Safety Car
Joined: Nov 2001
Posts: 3,753
Likes: 191
From: Orange County California
EXACTLY> summe rin ATL is HOT!!!!!!!!!!!!!!!!!!!! My C4 used to do the same thing from time to time. I think something is wrong. I can put in in defrost when the light is blinking and it will just still blink with no cold air. There is more to this story.
Safety Car
Joined: Sep 2000
Posts: 3,572
Likes: 420
From: Taildragers rule! USA1
>>Also should the a/c work when the defroster is on regardless??<<
No. Under the 35-40DegF the compressor stops working even in defrost mode. It would be nice if it continued to work, especially here in the NW where we get cool wet weather.
Best,
No. Under the 35-40DegF the compressor stops working even in defrost mode. It would be nice if it continued to work, especially here in the NW where we get cool wet weather.
Best,
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Drifting
Joined: Feb 2005
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If the outside temperature is such that the A/C should be blowing cold air and isn't, and the A/C light is either blinking or has gone off by itself, then the problem you've got is a short in the control head. I had this same problem on my daughter's Malibu which has the same A/C control head as the earlier C5's (manual controls) and I had to replace the control head. It can't be fixed (unless you've got an electrical engineering degree). Hope this helps.
Drifting
Joined: Feb 2005
Posts: 1,643
Likes: 167
I still think it's likely a short in the control head, whether it's manual or auto control. Problem is the auto control head is a lot more expensive to replace than the manual one. Only way to know for sure is to remove the control head and have it tested. Best of luck with this.
Intermediate
Joined: Feb 2005
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There are several different reasons that light will blink, the main reason is low freon level. The easiest way to see if there is some failure other than low freon, access the diagnostics from the dash and see if there are any hvac codes stored, if so, write the code number down, then clear codes accordingly. If system now functions, it is possible you what is called "logic lock up" and can happen when the battery is disconnected or othe voltage spikes occur.
Race Director
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From: Vancouver
2015 C5 of Year Finalist
St. Jude Donor '05-'06-'07-'08-'09-'10
Originally Posted by We Make'm Faster
There are several different reasons that light will blink, the main reason is low freon level. The easiest way to see if there is some failure other than low freon, access the diagnostics from the dash and see if there are any hvac codes stored, if so, write the code number down, then clear codes accordingly. If system now functions, it is possible you what is called "logic lock up" and can happen when the battery is disconnected or othe voltage spikes occur.
That's the best answer yet. I think this is where you should start too. No sense going in for the big kill if it's something that's easily corrected. Keep us posted. 
Team Owner
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
Thanks for the great info guys. I especially like the low freon answer......
.......don't care too much for the control head answer...... 
Mine's going in for a diag Saturday......I'll post the results.
Thanks again!
.......don't care too much for the control head answer...... Mine's going in for a diag Saturday......I'll post the results.
Thanks again!
Team Owner
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
Originally Posted by 04MSGCoupe
So what did you find out? Really interested to know outcome.
I was hoping you revived this thread to see what you had found out....looks like it was the other way around......
Burning Brakes
Joined: Jul 2004
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From: Spring Branch Texas
I recall that it takes something like 3 minutes of driving for the ambient air temp. sensor to get an accurate temperature reading to display. When I am pulling out of my neighborhood (always at the same speed) I can tell you within 10 ft. when my temp. reading will update.
Drifting
Joined: Feb 2005
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Originally Posted by 84zz4vette
I was hoping you revived this thread to see what you had found out....looks like it was the other way around......
I wasn't having the problem. I was only suggesting what I thought the solution might be.
Please let us know what the outcome is when you do get it resolved. I'd still be interested. Thanks.
Team Owner
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
Originally Posted by 04MSGCoupe
I wasn't having the problem. I was only suggesting what I thought the solution might be.
Please let us know what the outcome is when you do get it resolved. I'd still be interested. Thanks.
Please let us know what the outcome is when you do get it resolved. I'd still be interested. Thanks.
