Air con fan stalling

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mrscalex
Joined: Fri 13 Mar, 2015 09:14
Posts: 795

  Z3 roadster 1.9

Air con fan stalling

Post by mrscalex » Wed 10 Aug, 2016 18:07

I called my air con man (good guy) in to take a look at a squeaky compressor that I thought was seizing up. It turned out the compressor was just noisy and not seizing up. All the same it will receive some attention in due course to stop the squeak or will be replaced with my £18 second-hand bargain from ebay which my man said appeared to be perfectly serviceable.

The thing he was worried about was the air con fan grinding to a halt just when it should have been raising it's speed to bring the pressure down. He's fairly certain the bearings are binding as it warms up as it spins freely from cold.

So a couple of things I wanted to ask about.

1. Has anyone stripped a fan down before to service? Is this possible? It would have been standing for a long time before re-use so might just need some lube
2. He thinks there's an outside chance it might be a faulty pressure switch sending the wrong signal or even the ECU. I've got no error codes (of any type - hooray!). Could the pressure switch still be playing a part here. Or even the ECU?

If I need to replace it the pressure switch it is £90 from BMW. I *think* the OEM is TGK - commonly available in the States direct for considerably less. But I'm struggling to find a UK source or for a Behr/Hella which I'd probably tust too. Any ideas?
ImageImage
1999 Z3 1.9 Boston Green (Dimitri) - My brother's car owned from new and restored by me
2001 Z3 2.2 Topaz Blue (Trudy) - My car rebuilt from a write-off
2002 Z3 2.2 Titan Silver (Okus) - Project car waiting for a new engine
2001 Z3 2.2 Topaz Blue (Debra) - Donor car/breaker
1998 Z3 1.9 Boston Green (Allsworth) - Donor car/breaker now gone to Z3 heaven
Always happy to try and help with spares :)

NZ00Z3
Joined: Thu 23 Jun, 2016 02:26
Posts: 58

  Z3 roadster 3.0i

Re: Air con fan stalling

Post by NZ00Z3 » Thu 11 Aug, 2016 05:24

Which fan are you referring to?

1) The two speed fan in front of the radiator and A/C condenser?

2) The Fresh air fan located between the windscreen wipers?

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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 11:35
Posts: 9984

  Z3 roadster 1.9
Location: Cheshire

Re: Air con fan stalling

Post by Robert T » Thu 11 Aug, 2016 07:04

Z3 air-conditioning is a very basic on/off thing, with no sophisticated electronics, so there won't even be a module you can scan for error codes.

As for disassembly, I suspect the motor will be designed in such a way that you would have to destroy it to get it apart. I was wanting to do something similar to the fan on my other car and would have had to cut things to get it apart. Might be better to source a replacement if you can't lubricate it as is.

Cheers R.

Sent from my SM-G920F using Tapatalk
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Brian H
zroadster sponsor
Joined: Tue 16 Dec, 2008 19:55
Posts: 2502

  Z3 roadster 3.0i

Re: Air con fan stalling

Post by Brian H » Thu 11 Aug, 2016 07:58

If the pressure switch is faulty then the aircon compressor clutch will disengage also, maybe something to look at?

mrscalex
Joined: Fri 13 Mar, 2015 09:14
Posts: 795

  Z3 roadster 1.9

Re: Air con fan stalling

Post by mrscalex » Thu 11 Aug, 2016 11:23

My air con man said the compressor was working well apart from needing to be free'd up a little. He certainly wasn't concerned about the clutch. But that's useful info as it suggests there is nothing wrong with the pressure switch and my man thought that was unlikely anyway.

The fan does indeed look like a sealed unit. The locking tabs are formed by striking a cut in the middle and splaying either side out (like a mortice and tenon wood joint). Except the metal really is quite heavy gauge and I don't think could be manipulated by hand. The bearing that I think needs the attention is in the sealed end.

I do have a spare one and I'll go ahead and try that. Just wanted to get all my ducks lined up before starting the work.

Thanks.
ImageImage
1999 Z3 1.9 Boston Green (Dimitri) - My brother's car owned from new and restored by me
2001 Z3 2.2 Topaz Blue (Trudy) - My car rebuilt from a write-off
2002 Z3 2.2 Titan Silver (Okus) - Project car waiting for a new engine
2001 Z3 2.2 Topaz Blue (Debra) - Donor car/breaker
1998 Z3 1.9 Boston Green (Allsworth) - Donor car/breaker now gone to Z3 heaven
Always happy to try and help with spares :)

mrscalex
Joined: Fri 13 Mar, 2015 09:14
Posts: 795

  Z3 roadster 1.9

Re: Air con fan stalling

Post by mrscalex » Thu 11 Aug, 2016 11:24

NZ00Z3 wrote:Which fan are you referring to?

1) The two speed fan in front of the radiator and A/C condenser?

2) The Fresh air fan located between the windscreen wipers?
1) The two speed fan in front of the radiator and A/C condenser?
ImageImage
1999 Z3 1.9 Boston Green (Dimitri) - My brother's car owned from new and restored by me
2001 Z3 2.2 Topaz Blue (Trudy) - My car rebuilt from a write-off
2002 Z3 2.2 Titan Silver (Okus) - Project car waiting for a new engine
2001 Z3 2.2 Topaz Blue (Debra) - Donor car/breaker
1998 Z3 1.9 Boston Green (Allsworth) - Donor car/breaker now gone to Z3 heaven
Always happy to try and help with spares :)

handsomejackuk
Joined: Sat 18 Jun, 2016 11:35
Posts: 294

  Z3 roadster 1.9
Location: Blaenau Gwent South Wales...

Re: Air con fan stalling

Post by handsomejackuk » Tue 11 Apr, 2017 19:23

mrscalex wrote:
NZ00Z3 wrote:Which fan are you referring to?

1) The two speed fan in front of the radiator and A/C condenser?

2) The Fresh air fan located between the windscreen wipers?
1) The two speed fan in front of the radiator and A/C condenser?
quite interested in this myself, on how it all works....

i have air con 1.9 1998 m44 engine electric fan no viscous...

anyway when i press any of the air con buttons in side the cabin, the heater blower turns on to speed 1 which i suspect is correct.

but i thought i read somewhere that it should also engage the radiator fan on a low speed... is this correct, as mine doesnt ?

also i am trying to confirm that my radiator cooling fan (electric ) is operating.. now i can see the temperataure switch on the left side of the radiator, and the 3 wires, and did read that by shorting these wires it should bring on the radiator cooling fan high or low depending on connections yet to test this...

also... i may need to find out where the location of fuse 48 is.. rhd drive car can anyone help me locate it as i may need to confirm its not blown

thanks Al....

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colb
Joined: Sat 05 May, 2012 23:46
Posts: 566

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Air con fan stalling

Post by colb » Tue 11 Apr, 2017 20:24

I think you will find fuse 48 in the Aux Fuse Box under the glovebox judging by what I found on the web.
Just glad I don't have aircon on mine.
More info on this post on bimmerforums
https://www.bimmerforums.com/forum/show ... e-location

https://www.bimmerforums.com/forum/show ... -confusion
Colb
1999 BMW 1.8 Z3
1998 Honda Deauville NT650V

handsomejackuk
Joined: Sat 18 Jun, 2016 11:35
Posts: 294

  Z3 roadster 1.9
Location: Blaenau Gwent South Wales...

Re: Air con fan stalling

Post by handsomejackuk » Tue 11 Apr, 2017 20:30

fan is working at high speed... proved by shorting rad temp switch but no low speed... suspect a faulty radiator fan, or maybe someone would suggest any other tests ?

Al.

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