A/C not working on my 05' Passat Wagon

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swacapt

Member
Joined
Aug 14, 2011
Location
Apison, TN
TDI
2005 Passat wagon
Wow! There is a second relay panel behind the primary relay panel. There are three more radiator fan relays there. Two are labeled 373 and one is 370. There is also a very large (1+ inch across) blade type 40a fuse (below and left of the 370 relay). After finding and testing the three relays, I found the fuse. Well, that was it. Apparently when the fan died, it overheated and took out this big fuse. The #25 fuse on the main cabin panel however did not blow. Looks like I might have this fixed.
 
T

thundershorts

Top Post Dawg
Joined
Jul 15, 2010
Location
west chester pa
TDI
2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
glad I was able to point you in the right direction...
 
Q

Quest4TDI

Well-known member
Joined
Apr 22, 2005
TDI
Passat, '05, Candy White
Quest4TDI said:
I'm having similar symptoms as the original poster.

AC seemed to suddenly quit working from one day to the next, based upon what my wife has described to me (I rarely drive the Passat).

1) I pulled the 384 relay, and a quick visual didn't show any obvious signs of problems. May need to pull it again and check with a magnifying glass (middle-age eyesight sucks).

2) Check for operation of the passenger-side electric fan, and it comes on with the AC on.

3) Checked the AC fuse (fuse #25 if I recall correctly) and that fuse is fine.

4) Inside temperature display is operational

Any other diagnostics I should perform before I either decide to buy a replacement relay and easter-egg it to see if it does the trick, or before I go to an AC specialist to have the whole system checked? I don't believe we've ever had the freon recharged, but the sudden change would lead me to believe that it's not the freon unless there was a catastrophic failure.

If the compressor turns out bad, it looks like I should have the following replaced:
- the compressor (Sanden or Denso) (is a Sanden-Behr compressor the same brand?)
- the drier

- is there an orifice tube to replace?
- is there an expansion valve to replace?


thanks,
Herb
Click to expand...
384 relay bought from 1stVWparts solved the problem. AC is cold again.

Plan on inspecting my old relay with a magnifying glass to look for bad solder joints.


Herb
 
Scubanero

Scubanero

Veteran Member
Joined
May 30, 2007
Location
Calgary AB
TDI
2005 Passat Wagon
swacapt said:
Wow! There is a second relay panel behind the primary relay panel. There are three more radiator fan relays there. Two are labeled 373 and one is 370. There is also a very large (1+ inch across) blade type 40a fuse (below and left of the 370 relay). After finding and testing the three relays, I found the fuse. Well, that was it. Apparently when the fan died, it overheated and took out this big fuse. The #25 fuse on the main cabin panel however did not blow. Looks like I might have this fixed.
Click to expand...
I love these old threads. Now that AC season is here, I just found an entire trifecta: fan jammed with a rubber seal looking item that migrated from where it belongs, blown 40 A fuse and a loose solder joint on relay 384. I never did find a picture, but mine was on the pin 31 post. The solder joint may or may not have been a current problem as the jammed fan and blown fuse would account for everything. I am a bit curious about where the rubber came from, but have concluded that it did more harm than good, so won't be replacing it.
 
C

cappytom

Member
Joined
Sep 9, 2007
Location
Attica, IN
TDI
05 Passat GLS TDI, mocha brown
I sure wish I had checked here back in June when I too suffered the same trifecta as Scubanero. A chunk of rubber got caught in the aux cooling fan and broke the fan from the shaft. I replaced the fan but it would not spin with ignition on, ac switch on, and interior fan on. Was confused by another post that suggested a resistor bank needed replacement that is only accessible with the front end in service position. Decided to wait until I had time to get the car in that position. Never happened. Then found the info on the 384 relay, replaced it and the ac returned partially until I stopped at traffic lights or sat still for more than 20 seconds. Now I read the info on the 40 amp fuse for the aux fan. Replaced it and like magic I am back to cruising with instant ac whether standing still or rolling down the road. Thanks to all the contributors!
 
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