99 A4 - Fresh Air Blower Not Working

No problem, except many of the cars posted I do not own that specific manual, and might be addressed in the ones on my Jetta, but then again I might use information that would not be accurate for said models.

ON the later V configuration I have nothing to go on. Just trying to be the man my dog thinks I am.

Larimore.

Larry Manton said:

No problem, except many of the cars posted I do not own that specific manual, and might be addressed in the ones on my Jetta, but then again I might use information that would not be accurate for said models.

ON the later V configuration I have nothing to go on. Just trying to be the man my dog thinks I am.

Larimore.

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I was looking for info on current draw for a vehicle blower motor. Found a post by someone with a newer (early 2000's?) Jetta. On the highest speed with recirc going, that motor was drawing pretty close to 19 amps and runs on a circuit with a 25 amp fuse. Seems to be pretty close to what I'm seeing.

Jack@European_Parts said:

NO...........heat through the resistor block dissipates to rid the energy burned but the load increases at lower speeds and is why when a resistor block fails, it was due to not enough cooling of air over the fins/heat sink, further to maintain the function bridge of the resistor essentially blows like a fuse and you loose lower fan speeds.

FYI blower motor resistors traditionally fail on a high degree of humidity set on a low fan speed and usually being a very hot day where AC was required.

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It was the best of times, it was the worst of times. Up here, we were lucky enough to have the blower fail right when it's getting cold and a working defroster is key. Probably because we're in the north

Anyhow, always good to revisit some of the physics they tried to learn me with back on college.

It was the best of times, it was the worst of times. Up here, we were lucky enough to have the blower fail right when it's getting cold and a working defroster is key. Probably because we're in the north

Anyhow, always good to revisit some of the physics they tried to learn me with back on college.

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Physics .............ah a bunch of laws made up to restrict someone to an isolated box!
However these laws are meant & should be circumvented legally or when within a realm of a creative thought process in the spirit of helping humanity, not a profit point!

I consider them like moral values, but don't always live by them & if I think they are wrong..........

Back again...

After troubleshooting, identifying the PWM blower motor controller as the problem, but being unable to buy just a blower motor controller compatible with my vehicle, I went ahead and purchased a blower motor with controller from Parts Geek. Installed the new unit and besides the motor/hamster cage apparently being out of balance, everything was good. Fan worked and I had speed control. Just like the old days, only with more vibration.

Now, as of last week the motor has taken a dump but in a whole new way. The problem now is that the damn motor won't stop running. Try to change the fan speed, or even try to turn it off and you get no changes. Fan just keeps going regardless of what you do on the controller, that is until you turn the key off. A scan of the HVAC gives this:


I was able to do an output test before the battery on my laptop ran out, and found the control voltage went up or down in accordance with the fan speed. The measured voltage never changed. First thought was the connector to the blower as it was partially melted from the last failure, and I didn't change that. Went and looked at it and saw no changes there, and none of the individual wires are shorting out.

Given that a new fan/controller unit is now acting up, it makes me think there's something else wrong in the car. But, everything else seems to be functioning a ok. My next guess is the new blower/controller I purchased has a crapped out controller.

Thoughts? Suggestions?

Install factory parts and correctly start over.........

Jack@European_Parts said:

Install factory parts and correctly start over.........

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So, in other words you think the OEM part I purchased from Parts Geek is broken and should be replaced?

Any suggestions on how to pinpoint that is the issue before I seek my warranty replacement?

Nope ....
You induced the failure from probably poor install or your failure to inspect parts you received....right?
I mean seriously you ran it anyway & with a unit that was running improper right?
Are you sure your part is genuine?

Jack@European_Parts said:

Nope ....
You induced the failure from probably poor install or your failure to inspect parts you received....right?

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Okay, how do you suggest installing and using a part in and for it's intended use would induce failure? In any event, this does not negate my previous statement. That the new part is not functioning correctly (aka it's broken).

Are you sure your part is genuine?

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How can we be sure of anything? All I have to go on was the part catalog listing sold it as an "OEM Replacement" and the blower unit housing was stamped with a VW logo.

I don't drive the car (it's my wife's), but from what I know it's worked for the month-and-a-half since install. My last drive of the car last week was me taking it to the shop for an oil change and brake flush, that also wound up including a free coolant flush. When I dropped the car off, the blower was working correctly. When I picked it up the blower was in it's current failure mode. I didn't mention this originally as I really can't see how what they did would have any connection with the problem.

Aren't genuine parts available at the or your respective VAG dealer?
Did you follow the RTFB exactly to perform labor operations?

Jack@European_Parts said:

Aren't genuine parts available at the or your respective VAG dealer?
Did you follow the RTFB exactly to perform labor operations?

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I'd imagine they are, although all I called on was the blower motor control unit. Prices were significantly higher.

And yes, all 3 lines of remove/install instruction were followed.

And yes, all 3 lines of remove/install instruction were followed.

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Well than you must have shitty parts no, if you indeed followed the work procedures and used genuine parts with all new fasteners?

Jack@European_Parts said:

Well than you must have shitty parts no, if you indeed followed the work procedures and used genuine parts with all new fasteners?

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FWIW, got the car back from the shop earlier this week. They diagnosed the blower motor as the problem, and the problem with the blower motor caused the relay to trip to constantly on. In their trouble shooting, they unplugged the climate control head unit, and the motor just kept running. Plugging a new blower motor in made gave speed control back to the control head unit.

Cueing up a warranty return now and given the problems I've had with this unit, going to look at getting the part from a different vendor.

FOD right Scooby another Mystery solved?