No Air Conditioning - 2005 Cayenne Turbo

[SithPitt]

Ok, so here's the story. AC was working perfect. Out of the blue, zzzzzz no air. Nothing! Just dead :drive:.

 

Durametric Pro says typical code 353: "Feedback from blower regulator front, value below lower limit value"

 

 

Battery was replaced as it was giving me a hard time... It was replaced 2 days ago...

 

There's no voltage to the plug that goes to the blower...

 

No voltage to the blower blue regulator behind the glove box [plug with dual wires brown and black]...

 

Fuses are all perfect on the engine bay, right side, left side and even I checked the ones under the driver's seat that I didn't know there was a 40A and a 5A fuses when the battery was replaced. Curious thing is that I tested voltage delivered to fuse 57 and it was 10.38 volts....

 

All these tests were performed with the Cayenne running and AC fan at all different speeds.

 

I think I made a so far good troubleshooting but, don't know where else to look... I also checked the wiring diagrams, but feel kind of lost -_-   . I also made a search here at :renntech: but not as far as I have gone in the troubleshooting...

 

 

Any more ideas? :help:  :lightbulb:  :thankyou:

 

 

 

 

 

[bigbuzuki]

The red/yellow wire at the blower should always have 12 volts on it.

The black wire on the blower goes to ground through the regulator.

Try measuring from the red/yellow wire to a chassis ground and see If you get any voltage.

You can also put a fused jumper wire from the black motor wire to a chassis ground and see if the motor works. This will bypass the regulator and give you a clue if it's regulator or motor issues.

Edited April 19, 2015 by bigbuzuki

[SithPitt]

Tested... Thanks Bigbuzuki for your fast response!

 

Red/Yellow cable against chassis = 0.00v; Black cable continuity test to chassis = No continuity; Passenger Foot well light 12v against blower black cable 10.47 volts. Those 10.47v seems almost the same coming from fuse  57 which was 10.38v give or take... So regulator delivers the power to the fuse 57 and the fuse 57 to the fan blower?

[bigbuzuki]

You should have power to fuse 56.

Fuse 56 is for the front blower.

Fuse 57 is for the rear blower if fitted.

[SithPitt]

Ok. Both fuses have power...

[bigbuzuki]

The red yellow wire takes power from fuse 56 to the blower plug. Is there power at the plug now?

[SithPitt]

Sorry I'll have to check tomorrow. It's quite late here... But even as that I haven't perform any changes, so I guess is the same status...

[SithPitt]

Verified again this morning [fuses 56 and 57]... Still no power to the fan blower plug....

[bigbuzuki]

If you do have power at both terminals of fuse 56 and no power at the plug as measured from red/yellow and chassis, you must have a broken red/yellow wire from the fuse 56 to the plug.

[SithPitt]

I'll check for continuity, but still that's a heavy gauge cable... So it's very difficult to be broken since that are was not touch at all... I also checked BROWN cable of the regulator against ground and nothing... Weird thing is that BROWN cable against GROUND had continuity... Also, from the diagrams, I noticed that pin #B2, fan control I guess is the blue colored regulator, is the voltage feedback... Wild case could say that the regulator is fried and no voltage feedback could be received by the Durametric... I guess, by a 75%, regulator is fried...

 

Also noticed that the area surrounding the regulator, a.k.a. the whole enchilada [condenser, filter, etc.], was very, very cold so it's frozen the AC internally...

 

Bigbuzuki, still thanks! I noticed that this post have been a one-on-one troubleshooting guide :jump: