'91 AC blows hot air, suggestions?
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Joined: Jun 2002
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From: Colorado Springs CO
'91 AC blows hot air, suggestions?
I have a '91 convertible, and last week the ECC unit in the dash started giving the wrong outside temp. It would read 65 when it was between 85 and 90 outside. A couple of days later when the AC would kick on it would blow hot air. I checked the AC fuse, and tonight I replaced the ECC unit but the AC still isn't working. I think the physical components of the AC system are ok because even after it started blowing hot air every once in a while it would work and blow ice cold. Is there a relay or something else that I'm missing?
Thanks,
Thanks,
Burning Brakes
Joined: Dec 2000
Posts: 1,023
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From: Marietta, South Carolina, USA
Re: '91 AC blows hot air, suggestions? (91vert)
You may want to check the AC programer it is under the dash on the driver side hard to get too. sometimes they go bador maybe it has something to do whith outside temp sender.
Jay
Jay
Burning Brakes
Joined: Sep 1999
Posts: 786
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Cruise-In II Veteran
Re: '91 AC blows hot air, suggestions? (91vert)
I would run the built in fault diagnostics first.
To do this , push and hold the "Fan Up Arrow" and the "Fan Down Arrow" at the same time and hold it for about 5 seconds. The display should show "-00". Then push "AUTO" and the display will show any fault codes stored in the programmer.
00-not used
01-Temp, Door Motor Circuit Fault
02-Temp, Door Motor Circuit Fault
03-Ambient Sensor Open
04-Ambient Sensor Short
05-In-Car Temp Sensor Open
06-In-Car Temp Sensor Short
07-Solar Load Sensor Open
08-Solar Load Sensor Short
09-Low Freon Detected
10-UART Failure
To do this , push and hold the "Fan Up Arrow" and the "Fan Down Arrow" at the same time and hold it for about 5 seconds. The display should show "-00". Then push "AUTO" and the display will show any fault codes stored in the programmer.
00-not used
01-Temp, Door Motor Circuit Fault
02-Temp, Door Motor Circuit Fault
03-Ambient Sensor Open
04-Ambient Sensor Short
05-In-Car Temp Sensor Open
06-In-Car Temp Sensor Short
07-Solar Load Sensor Open
08-Solar Load Sensor Short
09-Low Freon Detected
10-UART Failure
Drifting
Joined: Oct 2001
Posts: 1,759
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From: Round Rock,Austin, Texas
Re: '91 AC blows hot air, suggestions? (Oh My)
You might wanna also check the space in front of the radiator and see if you need to clean out anything, like leaves and such. Sometimes that prevents the AC from working at full capacity.
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Joined: Jun 2002
Posts: 50
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From: Colorado Springs CO
Re: '91 AC blows hot air, suggestions? (RadPolo96)
I just checked the fan diags. I'm getting a code 09 - Low Freon Detected. Can I get this system recharged with Freon or will I have to have it converted to R134?
Thanks everyone for all the great info!
Thanks everyone for all the great info!
Thread Starter
Advanced
Joined: Jun 2002
Posts: 50
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From: Colorado Springs CO
Re: '91 AC blows hot air, suggestions? (91vert)
The only thing that bothers me about the Low Freon Detected code is that when this first started happening last week occasionally the AC would be ice cold..... :confused:
Thanks again for all the info., this is my first C4 so the Electronic Climate Control is kind of throwing me a curve.
Thanks again for all the info., this is my first C4 so the Electronic Climate Control is kind of throwing me a curve.
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Burning Brakes
Joined: Sep 1999
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Re: '91 AC blows hot air, suggestions? (91vert)
As the R-12 fill gets low it is NOT uncommon for the air conditioner to cycle from cold to warm and back again. Eventually, enough will leak out and there will be nothing but hot air coming out of the vents. The compressor clutch will not be engaging at this point.
The first thing that has to be resolved is to find where the leak is and repair that. Once that is done you can decide on whether to use R-12 or convert. R-12 is still available but is getting expensive. I converted to R-134 and it works okay, but I don't think it cools as well as R-12. You take your choice and pay your money!
[Modified by Wildride, 4:19 PM 6/6/2002]
The first thing that has to be resolved is to find where the leak is and repair that. Once that is done you can decide on whether to use R-12 or convert. R-12 is still available but is getting expensive. I converted to R-134 and it works okay, but I don't think it cools as well as R-12. You take your choice and pay your money!
[Modified by Wildride, 4:19 PM 6/6/2002]
