Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

A/C not working

Thread Tools
 
Search this Thread
 
Old Oct 14, 2010 | 03:24 PM
  #1  
shadowknight's Avatar
shadowknight
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Feb 2005
Posts: 714
Likes: 1
From: 3rd rock
Default A/C not working

This morning I was driving to work with the A/C on. After about five minutes I start to smell something burning then my center vent emits a grey smoke. I quickly turn off the HVAC fan and A/C. About three hours later I run the A/C again I hear a relay click but no cold air the HVAC fan works. I checked the sight glass on the dryer and don't see anything bubbling. I have noticed during the summer that the A/C was not cooling as well as it had in the past. Last night the HVAC fan blew the fuse but I don't see how that is related. What could cause the grey smoke from the vent?
Reply
Old Oct 14, 2010 | 03:37 PM
  #2  
Ethre's Avatar
Ethre
Pro
 
Joined: Aug 2010
Posts: 511
Likes: 0
From: 3rd Rock From The Sun
Default

Might be a good idea to look at your AC clutch. If the rubber's still supple and not cracking, that should be good (at least according to my local AC guy).

Have you ever checked your Freon (or equivalent)?
Reply
Old Oct 14, 2010 | 03:53 PM
  #3  
shadowknight's Avatar
shadowknight
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Feb 2005
Posts: 714
Likes: 1
From: 3rd rock
Default

I plan on evacuating the system this weekend using the guides from Wally,Tails and John Pirtle. I'm just concerned with that burned smoke smell it was not coming from the engine compartment but the vents inside the car. When I checked under the hood I could not smell anything burnt. Could it be oil from the compressor because of lack of freon or a bad component in the HVAC ducting system.

The car has front and rear A/C from what I can tell that means 2.0 lbs does that sound right.

Last edited by shadowknight; Oct 14, 2010 at 04:04 PM. Reason: updated
Reply
Old Oct 14, 2010 | 07:48 PM
  #4  
StratfordShark's Avatar
StratfordShark
Drifting
15 Year Member
 
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Default

Maybe the pcb relay for the A/C that lives inside the hvac controller has burnt out? It's actually under-rated for the clutch draw so a common failure.

If you follow the guides you can trace the voltage for the clutch all the way from the controller through the freeze switch, low pressure switch to the clutch. That will tell you what's failed.

You can also jump power to the compressor clutch to check it pulls in and compressor turns.
Reply




All times are GMT -3. The time now is 03:00 PM.

story-0
2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

Slideshow: The 2026 Porsche 911 Club Coupe is being resold $150K above sticker and that is a real problem.

By Joe Kucinski | 2026-05-21 11:52:54


VIEW MORE
story-1
Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

Slideshow: Talos Vehicles has transformed the Porsche 911 GT3 RS into a carbon-bodied, race-inspired machine that costs well over $1 million before the donor car is even included.

By Verdad Gallardo | 2026-05-19 13:39:04


VIEW MORE
story-2
9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-3
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-4
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-5
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-6
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-7
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-8
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-9
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE