AC support/supplement

[LEO]

I'm trying to find some insights regarding the AC support/supplement. The part in the image (green lines), which looks like a supplement and I suspect is not original (though I might be wrong), was apparently placed to house the bracket that moves and adjusts the AC accessory pulley.

Could someone help me identify if it's actually an original part? It has been lost, and I'm trying to figure out what I need to put there. If anyone has an image, it would greatly help me understand what to install.

Thanks to all,

 

[HB Chris]

Looks like you have the 74 and later axial compressor. These are basically not rebuildable and you won’t use that bracket with a rotary or Sanden compressor.

 

[LEO]

Regarding the Model 75, it appears to be the compressor you mentioned, and it was functional prior to disassembly. We've noticed that the part highlighted in green is missing. Do you happen to know if this is an original part? I anticipate we might need to have it fabricated, but my primary question is whether it is indeed the correct component for this model. Do you have any insights on this?

Thank you so much for your answers, which consistently provide valuable information I might not otherwise know.

 

[HB Chris]

Here is a diagram which may help:

https://www.realoem.com/bmw/enUS/showparts?id=3435-USA---E9-BMW-3.0CS&diagId=64_0872

Looks to me like a sleeve was there.

 

[Dlc]

general recommendation when you are rebuilding your car would be to upgrade to
-a modern Sanden-style compressor and brackets
-a parallel flow condenser

with a rebuild you have to get a new drier in any case.
Other points of wear and typical failure to be looked at would be
-your temp switch
-your blower switch
both can be easily and inexpensively replaced with new aftermarket products

I would consider this as preventive maintenance as you would not have to touch your AC system later on again

Thread 'DIY - Air Conditioning Updating with Sanden Compressor and Parallel Flow Condenser'

Jul 13, 2021

This DIY is subject to editing. More posts are being reviewed and information will be added.
I have tried to credit the people for their original posted information.
If there are errors or lacking information in here please let me know.

Air Conditioning Compressor and Bracket Selection

Posts were searched for this DIY:

Sanden compressor conversion brackets

Hello all, I have a very small one-man BMW restoration shop that I call L.C. Wylie & Co. and I also make and sell these brackets to convert your air conditioner to a modern Sanden type compressor. The original compressors are inefficient, expensive, and very hard to find a reliable new or...

e9coupe.com

@Stevehose did a great write up in 2011 as follows and some info was used:

Air conditioning upgrade photos/details

For those contemplating such a project, I recently completed my York to rotary a/c compressor upgrade. Keeping with R-12. In prior posts on this subject there weren't a lot of specifics so I am trying to offer some here for the novices like me. Project included: -switch from old York boat...

e9coupe.com

Book by...

• Dan Wood
• Replies: 21
• Forum: DIY - Do It Yourself Articles

• 

 

[Dlc]

general recommendation when you are rebuilding your car would be to upgrade to
-a modern Sanden-style compressor and brackets
-a parallel flow condenser

with a rebuild you have to get a new drier in any case.
Other points of wear and typical failure to be looked at would be
-your temp switch
-your blower switch
both can be easily and inexpensively replaced with new aftermarket products

I would consider this as preventive maintenance as you would not have to touch your AC system later on again

Thread 'DIY - Air Conditioning Updating with Sanden Compressor and Parallel Flow Condenser'

Jul 13, 2021

This DIY is subject to editing. More posts are being reviewed and information will be added.
I have tried to credit the people for their original posted information.
If there are errors or lacking information in here please let me know.

Air Conditioning Compressor and Bracket Selection

Posts were searched for this DIY:

Sanden compressor conversion brackets

Hello all, I have a very small one-man BMW restoration shop that I call L.C. Wylie & Co. and I also make and sell these brackets to convert your air conditioner to a modern Sanden type compressor. The original compressors are inefficient, expensive, and very hard to find a reliable new or...

e9coupe.com

@Stevehose did a great write up in 2011 as follows and some info was used:

Air conditioning upgrade photos/details

For those contemplating such a project, I recently completed my York to rotary a/c compressor upgrade. Keeping with R-12. In prior posts on this subject there weren't a lot of specifics so I am trying to offer some here for the novices like me. Project included: -switch from old York boat...

e9coupe.com

Book by...

• Dan Wood
• Replies: 21
• Forum: DIY - Do It Yourself Articles

• 

... not to forget the expansion valve (TXV) which also should be changed along with the drier when the evaporator is out - not too complicated and easy enough to obtain a new part from suppliers like Rockauto

 

[LEO]

... not to forget the expansion valve (TXV) which also should be changed along with the drier when the evaporator is out - not too complicated and easy enough to obtain a new part from suppliers like Rockauto

Thanks for the tips, about the temp switch and blower switch, is there any recommendation? SKU or site where to order those?

 

[sfdon]

You need to buy the temp switch or thermocouple at Napa and never buy it from BMW because the new one that they sell does not fit.
Our shop uses Indak three position off low high switch.
I would never use a switch that has resistor filaments in it unless you want a glow in the dark dashboard

 

[LEO]

Thank you all for the recommendations! Now I’m wondering what to do with a car that I might end up using maybe once a week at most—if I ever finish it. Air conditioning is definitely a must, but since I keep trying to make everything as original as possible, my mind starts working against me. The clear advice I get from all this is: change it and go for a modernized AC upgrade. Is there anyone actually in favor of preserving the original system? Or should I definitely just think about throwing it away? Big hug to everyone and wishing you a great start to the month!

 

[HB Chris]

I was once tempted to keep all of the original bits on my 2800 but I soon realized that the hoses are ancient and will probably not hold the R134 refrigerant, the drier needs to be replaced anyway, the original condenser is small and not very efficient, the expansion valve may need to be replaced (I did not do this even though it sat for 34 years, it worked fine), newer rotary pumps are much more efficient and quieter as well. The condenser and compressor are the two most worthwhile upgrades you can make.

 

[Dlc]

I would suggest you keep all the interior parts original - so it looks like stock - and modernize all the other parts.
Essentially, the main upgrade is the compressor + condenser, drier and TXV are just regular spare/wear items like break pads, and switches are just an add on.
You keep the knobs for the original look.

With a 50 year old car, I believe there is no harm in gently modernizing it whilst keeping an original look.

 

[Dlc]

temp switch eg UAC SW6495C (Rockauto)
TXV eg FOUR SEASONS 38604


blower switch discussed here:

Thread 'E9 A/C on-off, three position fan switch'

May 23, 2025

Looking for an A/C on-off, three speed fan switch.
Thanks, RedRV8tor

• RedRV8tor
• Replies: 15
• Forum: Parts For Sale and Wanted

and one more thing - include a binary/trinary pressure switch in your A/C setup, cheap to obtain but you invest in safety, plug into your drier

 

[alprada70]

Leo, yo tengo la platina del alternador.