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7 Series - E65 / E66 (2002 - 2008)
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  #1  
Old 09-06-2011, 08:09 PM
Atlantan Atlantan is offline
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02 e66 AC Blower ... impact

A few days back, my AC blower stopped working, had it fixed today. The blower motor and regulator had to be replaced. Didn't drive the car much over the weekend. I was going to schedule the fix later in the week but the Indy tech told me to bring in the car today. His reasoning was that the AC blower works in conjunction with the Radiator fan/auxiliary fan(?). Impact being a malfunctioning AC blower will keep the radiator/auxiliary fan(?) from running and potentially overheating the engine. True?

Please provide your expert feedback on the interdependency.

Cheers.
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  #2  
Old 09-02-2012, 10:25 AM
Big N Fast Big N Fast is offline
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Blower resolution?

Did you ever determine the connection between the blower motor and the auxiliary fan? My max blower only "kicks in" after 20 minutes or so. I planned on changing the blower regulator or blower motor but several posts indicate they have done so and seen no change. I do have mild suspicion that my electric (auxiliary) fan has a mild connection to the problem. I suspect a auxiliary fan problem since its operation is erratic. Normally these fans are on or off, but I seem to recall these fans are pulse modulating which means they are "kinda" variable speed. My fan blade also seems to have some "wobble" to it if I use a screwdriver to push on it when it is off. On the other hand, I see it running full speed at some points...not sure of the logic in the fan operation.

If you have any recollection as to what fixed your problem, please advise.
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  #3  
Old 09-02-2012, 11:49 AM
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7Figurez 7Figurez is offline
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Quote:
Originally Posted by Big N Fast View Post
Did you ever determine the connection between the blower motor and the auxiliary fan? My max blower only "kicks in" after 20 minutes or so. I planned on changing the blower regulator or blower motor but several posts indicate they have done so and seen no change. I do have mild suspicion that my electric (auxiliary) fan has a mild connection to the problem. I suspect a auxiliary fan problem since its operation is erratic. Normally these fans are on or off, but I seem to recall these fans are pulse modulating which means they are "kinda" variable speed. My fan blade also seems to have some "wobble" to it if I use a screwdriver to push on it when it is off. On the other hand, I see it running full speed at some points...not sure of the logic in the fan operation.

If you have any recollection as to what fixed your problem, please advise.

Your issue is most likely related to an Under voltage situation. The power module will reduce the fan speed when it detects there is an under voltage in the system. Once the system reaches the correct operating voltage the fan speed will return to normal operation. I would check the operating voltage of the system right after you start the car. The system should stabilize at 14.0V when the car is sitting idle, +/-0.5V deviation.
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  #4  
Old 09-02-2012, 04:57 PM
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sirstopher sirstopher is offline
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Quote:
Originally Posted by Big N Fast View Post
Did you ever determine the connection between the blower motor and the auxiliary fan? My max blower only "kicks in" after 20 minutes or so. I planned on changing the blower regulator or blower motor but several posts indicate they have done so and seen no change. I do have mild suspicion that my electric (auxiliary) fan has a mild connection to the problem. I suspect a auxiliary fan problem since its operation is erratic. Normally these fans are on or off, but I seem to recall these fans are pulse modulating which means they are "kinda" variable speed. My fan blade also seems to have some "wobble" to it if I use a screwdriver to push on it when it is off. On the other hand, I see it running full speed at some points...not sure of the logic in the fan operation.

If you have any recollection as to what fixed your problem, please advise.
Register your battery with INPA and your max AC will work.
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  #5  
Old 09-02-2012, 05:01 PM
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sirstopher sirstopher is offline
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Quote:
Originally Posted by Atlantan View Post
A few days back, my AC blower stopped working, had it fixed today. The blower motor and regulator had to be replaced. Didn't drive the car much over the weekend. I was going to schedule the fix later in the week but the Indy tech told me to bring in the car today. His reasoning was that the AC blower works in conjunction with the Radiator fan/auxiliary fan(?). Impact being a malfunctioning AC blower will keep the radiator/auxiliary fan(?) from running and potentially overheating the engine. True?

Please provide your expert feedback on the interdependency.

Cheers.
The secondary fan located in front of the radiator is controlled by the AC system, so when the condenser trips the circuit the front secondary fan kicks on to cool the motor.

So yes in theory your Indy is correct, with the AC off I don't think the fan kicks on.
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  #6  
Old 09-03-2012, 08:58 AM
Big N Fast Big N Fast is offline
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Thanks guys but I checked the battery voltage and it is at 13.8 to 13.9 as checked by a meter as well as unlocking the menu using the reset button and inserting the code for my VIN. I did see that the aux fan does go to what appears to be high speed when it is running. Just to clarify, my blower does work, but seems to be at a lower speed as it will "kick in" after 20 minutes or so. When I hit the max ac, the rear ac immediately goes to full blast. It's a 760 so I am not sure all 7's have the roof mounted rear ac as mine does. I suspect the blower regulator which is $200 as the blower does work and does go to high after some amount of time. Just don't want to throw $200 away as so many have had the same problem - just seems others have done this and it did not work. Appreciate the advice!
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  #7  
Old 09-03-2012, 10:06 AM
Big N Fast Big N Fast is offline
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Also, my batty is newer (18 mos old) and was registered. Do not have any battery warnings ever since battery was replaced.
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  #8  
Old 09-03-2012, 08:05 PM
Big N Fast Big N Fast is offline
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Just switched my rear blower regulator and front blower regulator - rear still works, front still only blows on low and med...does not seem to blast. Maybe I am imagining but it seemed to blast harder once upon a time. ANyway, I have ruled the blower regulator and aux fan out as they seem fine. Might change the bblower as it's not horribly expensive. Battery voltage always in the 13.8 to 13.9 range.
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  #9  
Old 09-03-2012, 08:22 PM
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sirstopher sirstopher is offline
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Originally Posted by Big N Fast View Post
Also, my batty is newer (18 mos old) and was registered. Do not have any battery warnings ever since battery was replaced.
Where and how was it registered?

The reason I asked before is my max AC didn't work at all untill the car was running for about 15 to 20 min, then it would kick on. I purchased a new battery and it would again do the same thing, I had the shop re register the battery twice. I then purchased a cable and registered my battery with INPA, my fan has worked fine ever since.

Test- turn on the front defroster, think its the first button on the left. If the fan runs high, you have a problem with the power module supplying power to the switch on the fan when the AC is on.

This is how I got mine to finally work, I have a switch, final stage resistor, fan ect sitting in my garage, all still un-used because the battery was not registered at BMW. I had two different mechanics tell me that my battery was registered.

If its not registered with the gt1 software or INPA you will always have voltage problems.

Check the front defrost fan speed and check back, I bet it turns on high speed......
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  #10  
Old 09-03-2012, 08:30 PM
Big N Fast Big N Fast is offline
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OK, I am sold. You are correct. I also see that when I hit defroster, the fan speed modulates in many different speeds vs approx 3 sppeds as it does now. Thought I was imagining it used to blast - sounds like you were correct. I guess you are also saying I need to register battery...can a dealer really be that inept that they cannot do it correctly. I recently used my friends Snap On unit when I was clearing a code and registered the battery myself - just for kicks. Is there something special about the gt1/inpa registration? Again - thanks for clarifying I have a problem.
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  #11  
Old 09-03-2012, 08:43 PM
Big N Fast Big N Fast is offline
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Battery recharge light came on in three minutes with "key on". Time to learn how to register battey with INPA.
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  #12  
Old 09-03-2012, 10:51 PM
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sirstopher sirstopher is offline
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Yep, we are here to help each other, BMW would have ripped everything out and replaced. Most know nothing about these cars on a daily level.

I imagine that when you re-registered the battery that may be when the power module seemed to not allow the fan full power??????

INPA is the only tool I know that can fully register your battery, use nothing else. Funny thing is that it takes 3 seconds to register it.
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  #13  
Old 09-04-2012, 08:39 AM
Smiley27 Smiley27 is offline
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Sristopher is absolutely correct. Without registering the battery you will get alot of yes symptoms that people usually over look and never realize that the battery is the issue.

The more technology in a car the more reliant on the battery it is. Any issue with the battery and you will never ever see the end of it.
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  #14  
Old 09-04-2012, 08:58 PM
Big N Fast Big N Fast is offline
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Yes he is!

Sristopher,
There is a beer and lobster tail with your name on it waiting in Cincinnati! I called the Indy that installed the battery (OEM from BMW) and they said they would gladly re-register it. Naturally, they said it was a waste of time, it might cause other problems, etc. But when it immediately worked, they just shook their heads! Not sure of the accuracy, but they said to register the battery, their tool (could not identify the brand) wanted to see 14.6 volts and it is only putting out 13.9 or so. I did not leave the accy on and see if the "recharge" light comes on...I think I'll get used to having awesome ac for a while. Besides, I still have two things wrong before I go looking for more weekend projects.

1. My GPS recently began to show that I am somewhere else.
2. My dynamic drive fault comes on from time to time when I get too aggressive...and the only thing cooler than the 760 acceleration is the awesome handling!

After that, I will have a flawless 760!

Thanks and a handshake!
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  #15  
Old 09-04-2012, 09:11 PM
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sirstopher sirstopher is offline
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Thank for the PM and the thanks. In return you know more than what you started with so share when ever possible. My own process took me 4 months and I ended up buying the cable, another member helped me out so pass it on.

As for the gps, take the DVD out and drive the car around some, then stick it back in and see if it will sync up? I don't know if this works or not, just an educated guess????

The dsc light flashes on my car also, I think it's just warning you that it has been activated when driving like a bat out of hell.

Enjoy the cold AC.

Chris
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