blained

Hi all,
My wife's Cayenne had the front air blower doing the usual symptoms, groans, slowing down, etc. etc. I'd replaced this one several years ago, so was getting ready to do it again. Then one day she said it stopped, and blew smoke out of the vents, so she pulled over. I told her to turn the AC off and continue home, then ordered the motor and regulator from Pelican Parts.

The swap-out went perfectly and I was congratulating myself on my expertise until I tried turning it on. Still dead to the world. I logged in and started reading all the posts on here about this !#@$ situation. Still no solution, here's what I've done so far:

I checked the fuse and swapped it around with some of the other 40A fuses, with no change.
I measured 12v at the red/yellow wire to the blower motor.
I decided to try plugging back in the old motor which did nothing so I hooked the new one back up. Then I tried the old regulator.
When I replaced the old regulator, it accidentally touched the metal frame with its fins and the fan started blowing full force. However, it would not turn off even with the keys out (which is what clued me into finding the accidental grounding). This makes me think that by grounding itself, it was able to power the fan, which makes me suspect the ground wires to the regulator, maybe?

Anything else I can try before taking it to the dealer?

Thanks,
Blaine

deilenberger

It almost sounds as if they're regulating the speed with the ground connection. That would be rather bizarre. Let me poke into the wiring diagram (be patient - it's 11,000 pages, about 300 wiring diagram pages..)

Yup, bizarre. The black wire is NOT ground. It is the control circuit for the fan speed. The red/yellow goes directly to a fuse - hot at ALL times (meaning if the controller goes blooey it can result in the fan running without the ignition on.. "blooey" is a French tech term.. it's = to Kaput in Germanish.)

SO - by grounding the case - somehow that also grounded the black wire. It would seem a bit odd to have something wired that way, but we're already in bizarro land with the ground being used for speed regulation.

The ground wire to the regulator is the BROWN wire (ALL brown wires are ground, and all ground wires are BROWN - it's a German thing..) Goes to Pin A1 of the control unit. Certainly might be worth checking if it's getting a good ground. If it is - it would seem more than likely the control unit has gone tango-uniform (TU - another tech term from the US Army I believe..) except you've already replaced it right?

The brown/black wire comes from the "Climatronic Control Unit" - and appears to be the activation signal that controls the fan control. Since it's brown/black - it may well be a switched negative of some sorts (diagrams don't tell).

Red/Gray - is the "SUPPLY VOLTAGE" - also coming from the Climatronic. I'd expect to see 12V on that - it's the power for the electronics in the control module.

Orange/yellow - is "FEEDBACK VOLTAGE" - again - Climatronic. I have no idea what it's supposed to show.

GOOD LUCK! Or you can try the dealer I guess. I have heard of the control unit going bad (the Climatronic - the bit with buttons and switches and levers in the dash.)

blained

Deilenberger,
Thanks much for the deciphering - that makes sense that the black wire is a control signal and NOT ground, since as you mention, for some reason as long as I recall, the Germans have decided brown means ground (=earth perhaps?).

I was hoping it was not the Climatronic as I bet the cost for one of those installed at the dealer may nearly total the vehicle! The sad thing is that apparently the code readers suggest the main controller unit even in the case of simple fan/regulator replacement situations, from what I read on here.

The Climatronic unit appears to function 'normally', indicating fan up/down speeds and such, even raisinng/lowering it in Auto mode (though minimally since obviously without it blowing, the results in Auto are not exactly going to change much). Of course, right there I guess I'm contradicting myself, since 'normally' would imply the fan indicator on the screen would be accompanied by similar fan activity. I realize that could just be the controller living in fantasy-land, and my old Durametric setup is kaput right now, so...

Thanks again,
Blaine "Hello Mr. Dealer?" DeLancey

J'sWorld

deleted

blained

Yeah, I think I was confusing the Climatronic's cost with the PCM module. I think I may give the eBay thing a fling, as the installation is a piece of cake. I also saw Suncoast had new ones for $430. Only risk I see going the eBay route is that it ends up being defective too, and I get diverted thinking it's some other issue. I think I can manage at those prices, though!

blained

Don/Mr. Haney,
Thanks for your replies, and I did get a very nice Climatronic for $88 shipped via e-Bay (could have had it for $80, but I paid for fast shipping to get it by the weekend). Installed it, no change in things. Basically I hear the various flaps opening and some other activity, but the fan never starts blowing even though the indicator on the Climatronic shows the speed ramping up.

I tried to hook up my old Version 5 of the Durametric software that was on an old laptop, since I had issues installing Version 6 under a Win 7 Parallels VM on my new machine, and had mixed results. My thinking was maybe I needed to try recoding the unit. However, although I could monitor some live stats and even recoded it to the existing code of 30 (I didn't have a clue what other values to try, so I just recoded the existing value), I could not get it to read faults or make it through the tests if I recall. Anybody else find Durametric to be pretty buggy? Or that CAN bus seems to operate at about 110 baud?

Unless you have any other ideas, and those diagnostics were really helpful, I've got an appointment Monday at our local dealer, so I'll just let the pros deal with it. At least I learned some stuff about the vehicle and didn't get too far into my wallet to gain the experience!

Thanks,
Blaine

deilenberger

Without digging into the wiring diagrams again.. I'll ask what I hope isn't an insulting question..

After replacing the Climatronic - you did check all the HVAC related fuses again right? I was just thinking if the old one caused a fuse to go out..

blained

Don,
Don't worry, there are no insulting... wait, yes, I've been asked MANY insulting questions in my life, but anyway, no, no insult taken. Your post prompted me to run downstairs and once again check the main fuse in position 56, HOPING that was all it was, but alas, no such luck. So the 9:00 am appointment at the dealer holds for tomorrow. I'm still hoping it's something stupid, but now I'm fearing that smoke my wife described might be wiring harness rather than blower fan... If it were Lucas electrics instead of Bosch I would just have figured it was the regular release of smoke pressure in the wiring, but that too I'm afraid is a pipe dream...

I'll respond back with whatever the final answer is just to add to the archives on modern Porsche HVAC fun. I hope it's not too embarrassing.

Thanks,
Blaine

deilenberger

Blaine - certainly looking forward to the resolution. The reason I mentioned the diagram - I think there might be more than one fuse involved.. there is a main fuse to the fan - powering it. There probably also is a fuse going to the control unit for the fan. Probably. Mebbe. I just spent a bit of time looking, but without printing them up and matching the edges to make continuous diagrams it's difficult to tell.

Let us know what the dealer figures out..

Best,
Don

blained

Well, I feel a little foolish,but I think I still got out 'under dealer cost' and learned a little more about the HVAC system. It turned out the last straw was a bad pin connector, I believe on the motor. The original motor needed replacing anyway, but I wish I'd have figured out this last bit. I didn't get to talk directly to the mechanic, as he'd already taken off when I got there and I haven't had a chance to stop by since, so I'm wondering if it was damaged during the short that caused the smoke or somehow when I was replacing it, but either way, the AC now blows nice and cold. So, for those tuning in late, if all else fails (or doesn't seem to), check those connectors!

Anybody need a very nice Climatronic unit? (I put the original one back since it wasn't the issue)

Thanks for all your help,
Blaine

deilenberger

Blaine - thanks for reporting back. It was great to see it wasn't left hanging as a mystery where the reveal was never done..

ginopio

Hello! Sooo.. I've been having this same issue.. starts blowing, groans, then nothing. This just started out of the blue.. Do I need to replace a blower motor? or ?? Sorry, just trying to learn what happened and how to fix it. Good news, no smoke!

Thanks! G

deilenberger

The smoke just hasn't been delivered yet. The quick answer is - yes - it's the blower motor. Do you need to replace it? Probably - but I can't recall ever seeing anyone trying to lubricate the bearings in the old ones.

Long-story-short: Ya know the usual Chinese plastic fans? The ones that work REALLY well when new - and usually within 2 years, slowly stop turning? I've revived quite a few of these (all I've tried) by disassembling and lubricating the motor bearings. They use a sintered-bronze bearing - which by design is supposed to absorb oil into the voids due to sintering, then slowly release it as the bearing is used - to lubricate the shaft/bearing interface.

It seems the Chinese are using some high-volatility oil - since the bearings dry up in a year or two of use - and start binding.

I've fixed these by giving them a shot of light lubricating oil (like sewing machine oil) and letting them soak overnight. Once the oil has soaked in - the bearings once again turn freely. In my garage I have two of these fans - both of which packed it up in about 2 years of use. Since I oiled them - they are going on 12-15 years now of fairly regular use.

I think it might be worth trying to oil the HVAC fan motor bearings on the Cayenne/VW HVAC assembly. It might just last about forever with the oil refreshed. Benn meaning to pull mine out and do it since my fan on the '11 CTT often throws an over-current fault on the HVAC code readout. It starts up fast, slows down for a second, then returns to fast. The bar-display on the HVAC displays don't change.

Gotta get to that real soon.

If you don't decide to oil yours - the one for the same year VW Tourag will go right in - it's identical and can be found with a bit of Googling for a fraction of what Porsche wants for the identical item (they don't even put a Porsche parts sticker on it - it comes with the VW sticker on it..)

trungvip0195

You can buy yourself a different air blower it is old. You see the air blower here Aeration machines

redstack

So rock auto and parts geek have both 4 seasons and Uro fan motors, for under $100. Any thoughts on whether one is better than the other? Is uro made in Europe by chance? Maybe i should prelube the bearings with a good oil like triflow or something in case that might extend the life of the non-oem fan.