AC geniuses please step up...got a weird one.

rsfeller

Well-known member
Joined
Oct 6, 2008
Location
Central Ohio
TDI
1996 Passat
Thought I had the common compressor solenoid on our 2011 JSW that runs the Sanden 16 model. Ordered a new solenoid from a well rated seller and had my reluctant local shop suck, swap and blow the freon back in.

My AC went from working 90% of the time to 100% dead. I really thought I had the common solenoid failure that can conk out at low RPM or high RPM but works pretty darn well most of the time. Accepted the fact I prob got a bad compressor and tech said it had the same pressure readings on high and low side, so...

Was saving up for a full DIY rebuild of the system.

Forward to three weeks later after all the 94F weather is over and I'm on the free way today doing 65MPH with the windows and sunroof open and all of a sudden my feet start freezing. I look at the HVAC system and the AC button is OFF...100% OFF. I clearly have AC coming from vents on a 80F day. I turn the button on and for the next hour I have AC. No issues at low or high speed, idle ect. Drove home and put inferred gun on it and it's shooting 42.5F out the vent at 80F ambient (60%).

*** is going on with the AC running with the switch off?

I'll update more tomorrow to see if this was a fluke or resurrection from something clogged (unreleased to previous issue).

I can add that it seemed that often the fan speed has an over drive when on 3 or 4 that will increase RPM/speed and allow AC to kick on in the past. I even got crazy for a moment when I thought turning on recirculation would engage AC...so maybe I'm dealing with a wiring/computer issue here rather then hardware?

Also, and VCDS testing I can do?
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
OBD works, start there. The Climate has the ability to store and display DTCs, has observable data, and even some other things, just like any other module in the car.
 

JELLOWSUBMARINE

Veteran Member
Joined
Mar 3, 2014
Location
yes
TDI
2011 Jetta Sportwagen, 6M, red/tan, navi, pano, 83 5m diesel pickup, 82 p/u trailer,.04 5.5 TDI Passat wagon (gone), 80,81,82 diesel p/u (gone), 80,82 sportruck (gone), 59 passthru bus (long gone), 79&87 westy (gone), 57 baja bug (long gone), 73 914
OBD works, start there. The Climate has the ability to store and display DTCs, has observable data, and even some other things, just like any other module in the car.
Thats interesting. When my typical RCV related issue acted up the fan speed had a mind of its own. Air flow would choke down (seemed like internal door flap closed??). This was only when not cooling properly as I recall. Please post the DTCs if your able. Ive been out of the a/c feild for awhile and am amazed by the a/c tech improvement.
 
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