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Retrofitting AC

Posted: Sun Sep 12, 2021 6:35 pm
by onthames
So... I acquired a full AC system from a 325i that is being broken. Good price too. How complex is the conversion from R12 to 134a. I understand BMW still sell a conversion kit (82319067394) but are there any other parts I need to change? I have heard that the compressor needs to be changed but haven't found any solid info on this.

If only Brian was around! I'm sure he'd know.

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 6:42 pm
by twenty
Barry @ BMR Performance is your man. I believe he's done quite a few conversions and retrofits.

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 6:44 pm
by onthames
twenty wrote:
Sun Sep 12, 2021 6:42 pm
Barry @ BMR Performance is your man. I believe he's done quite a few conversions and retrofits.
I'd quite like to do it myself... Lots of time to spare as I've just finished uni. I'm sure Barry would have it done in a day but I think I could stretch it out to a few weeks... Would be a good excuse to stay in the garage all day tinkering!

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 7:53 pm
by flybynite
onthames wrote:
Sun Sep 12, 2021 6:35 pm
So... I acquired a full AC system from a 325i that is being broken. Good price too. How complex is the conversion from R12 to 134a. I understand BMW still sell a conversion kit (82319067394) but are there any other parts I need to change? I have heard that the compressor needs to be changed but haven't found any solid info on this.
If only Brian was around! I'm sure he'd know.
The conversion kit is NLA but items are available separate from BMW and places like autodoc. New receiver/drier will be a must as will a new expansion valve.

There were some compressors that were not able to run R134a (I am sure there was a thread on that, year or so ago)

Pipes were available new last year but probably more than you paid for the kit. Depends on how rusted yours are.

Many say you need a parallel flow condenser like the one made by Nissens to work best with R134a.

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 8:00 pm
by onthames
Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 8:59 pm
by flybynite
onthames wrote:
Sun Sep 12, 2021 8:00 pm
Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!
Found it :D

viewtopic.php?f=2&t=280358&p=2971860&hi ... r#p2971860

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 9:18 pm
by onthames
flybynite wrote:
Sun Sep 12, 2021 8:59 pm
onthames wrote:
Sun Sep 12, 2021 8:00 pm
Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!
Found it :D

viewtopic.php?f=2&t=280358&p=2971860&hi ... r#p2971860
Awesome. Looks like mine is compatible then. Some sites are showing the retrofit kit in stock so I'm going to call Cotswold tomorrow... Could be in luck.
May change out the condenser as that thread talks about. Seems like they're pretty cheap as opposed to the compressor which is €800 for a refurbed one from BMW!

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 10:15 pm
by Cloggy Saint
When I converted from R12 to R134a I kept the original compressor and it all works fine.

Re: Retrofitting AC

Posted: Sun Sep 12, 2021 10:26 pm
by onthames
Cloggy Saint wrote:
Sun Sep 12, 2021 10:15 pm
When I converted from R12 to R134a I kept the original compressor and it all works fine.
Did you swap the condenser or anything else? Glad to here your compressor works fine. What years the car out of interest

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:12 am
by Cloggy Saint
This was years ago so I can't exactly remember what was changed. I think the only major components were the condenser and dryer, the rest was seals and various small parts. The car is from '89. Did you get the fan with your kit? I struggled to replace my seized one about 12 years ago!

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:27 am
by onthames
Cloggy Saint wrote:
Mon Sep 13, 2021 12:12 am
This was years ago so I can't exactly remember what was changed. I think the only major components were the condenser and dryer, the rest was seals and various small parts. The car is from '89. Did you get the fan with your kit? I struggled to replace my seized one about 12 years ago!
Yep, got the fan, I think! It's still in the donor car and is all working it seems, just no r12 in the system but compressor etc turns on and idle revs go up. So I should have a complete system when it's all out. I'm wondering, when did BMW do these r134 conversions? Because it may already be converted. Not sure how to tell.

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:30 am
by Cloggy Saint
If it was done by the book it would have a R134a sticker on/around the right hand turret.

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 3:03 am
by Tzantushka
*raises hand*
Yep - converted a R12 system to R134a last year.
You'll see more detail here

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:13 pm
by onthames
Tzantushka wrote:
Mon Sep 13, 2021 3:03 am
*raises hand*
Yep - converted a R12 system to R134a last year.
You'll see more detail here
Awesome this should help. Unfortunately Cotswold confirmed the conversion kit is NLA.

It looks like I have the choice of the following dryer brands: Apa, Mahle

And the switch appears to be 64538390971... Which seems to have some replacements on autodoc

But, I cant for the life of me find these parts:
"R134a service valves with caps

R134a o-rings"

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:27 pm
by flybynite
onthames wrote:
Mon Sep 13, 2021 12:13 pm
Awesome this should help. Unfortunately Cotswold confirmed the conversion kit is NLA.
It looks like I have the choice of the following dryer brands: Apa, Mahle
And the switch appears to be 64538390971... Which seems to have some replacements on autodoc
But, I cant for the life of me find these parts:
"R134a service valves with caps
R134a o-rings"
For me Mahle for the dryer but they are a service item and don't last forever so not a problem either way just dont open it to moisture before fitting and check it has not been on the shelf too long, they have a date.

Other items are standard parts and can be had from any good aircon spares place, there were 2 sizes of valve so just check what you have before ordering.

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 12:33 pm
by onthames
flybynite wrote:
Mon Sep 13, 2021 12:27 pm
onthames wrote:
Mon Sep 13, 2021 12:13 pm
Awesome this should help. Unfortunately Cotswold confirmed the conversion kit is NLA.
It looks like I have the choice of the following dryer brands: Apa, Mahle
And the switch appears to be 64538390971... Which seems to have some replacements on autodoc
But, I cant for the life of me find these parts:
"R134a service valves with caps
R134a o-rings"
For me Mahle for the dryer but they are a service item and don't last forever so not a problem either way just dont open it to moisture before fitting and check it has not been on the shelf too long, they have a date.

Other items are standard parts and can be had from any good aircon spares place, there were 2 sizes of valve so just check what you have before ordering.
Sweet. Do you remember what brand you used for the switch? P/N 64538390971
Appreciate the help

afaik it doesn't look like its already been converted
9999.jpg
9998.jpg

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 1:20 pm
by Tzantushka
Agree with the Mahle dryer.
If you want some more detail shoot me a PM and I can dig out the parts list.

With the high and low side ports just make sure you order some short ones as if the R134a adapter is too long it will foul on the bonnet hinge.

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 1:30 pm
by onthames
Tzantushka wrote:
Mon Sep 13, 2021 1:20 pm
Agree with the Mahle dryer.
If you want some more detail shoot me a PM and I can dig out the parts list.

With the high and low side ports just make sure you order some short ones as if the R134a adapter is too long it will foul on the bonnet hinge.
Awesome, have sent you a PM and will keep adapter in mind.

I'm hoping the pipes are all OK as they look pretty rusty externally. Donor car has been dry stored for 12 years. Hopefully they are okay internally and I can clean them up.
ab541.jpg

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 2:51 pm
by flybynite
onthames wrote:
Mon Sep 13, 2021 12:33 pm
Sweet. Do you remember what brand you used for the switch? P/N 64538390971
I think I bought that from BMW, like I said all bits were available separately but that was last year so not sure about now. What manufacturers have you seen? For me it would be something like Mahle, Hella/Behr or Delphi

Re: Retrofitting AC

Posted: Mon Sep 13, 2021 3:12 pm
by onthames
flybynite wrote:
Mon Sep 13, 2021 2:51 pm
onthames wrote:
Mon Sep 13, 2021 12:33 pm
Sweet. Do you remember what brand you used for the switch? P/N 64538390971
I think I bought that from BMW, like I said all bits were available separately but that was last year so not sure about now. What manufacturers have you seen? For me it would be something like Mahle, Hella/Behr or Delphi
Unfortunately the switch is NLA from BMW. I could only find one switch in stock which said it fitted which was this cheapo thing https://www.autodoc.co.uk/nrf/2389338

Re: Retrofitting AC

Posted: Tue Sep 14, 2021 9:27 am
by flybynite
onthames wrote:
Mon Sep 13, 2021 3:12 pm
Unfortunately the switch is NLA from BMW. I could only find one switch in stock which said it fitted which was this cheapo thing https://www.autodoc.co.uk/nrf/2389338
If it's the only one easily available then it should do, it is only a pressure switch. Give it a year or so parts may come available again once thins start up.

Re: Retrofitting AC

Posted: Tue Sep 14, 2021 11:38 pm
by onthames
Guys. this may be a dumb question but I'm interested anyway... Would a system taken from a LHD car fit into RHD? Guessing not but thought I'd ask.

Re: Retrofitting AC

Posted: Wed Sep 15, 2021 12:19 am
by Cloggy Saint
Certainly everything up to and including the heater box. I'd be surprised if there was a difference but you never know. Check on realoem, that may tell you.

edit
The wiring may be different too, where does a rhd ecu live? :?

Re: Retrofitting AC

Posted: Wed Sep 15, 2021 12:30 am
by onthames
Cloggy Saint wrote:
Wed Sep 15, 2021 12:19 am
Certainly everything up to and including the heater box. I'd be surprised if there was a difference but you never know. Check on realoem, that may tell you.

edit
The wiring may be different too, where does a rhd ecu live? :?
Real OEM diagrams look identical... Hmm. The RHD ECU is on the drivers side, under the knee panel

Re: Retrofitting AC

Posted: Wed Sep 15, 2021 12:55 am
by Cloggy Saint
My lhd ecu is above the glove box so that's probably the same too.

Re: Retrofitting AC

Posted: Wed Sep 15, 2021 1:02 am
by onthames
Cloggy Saint wrote:
Wed Sep 15, 2021 12:55 am
My lhd ecu is above the glove box so that's probably the same too.
Heater control panel is definitely different though as it's mirrored right? Maybe this is just on the user inferface level and the backend is all the same. Dunno.

Re: Retrofitting AC

Posted: Thu Sep 16, 2021 8:22 pm
by onthames
Hi guys.. Somewhat urgent:

So, the donor car for AC has the AC loom with the main loom, was hoping they were seperate. Seller wants to keep the main loom which has the AC loom in it loom. Has anyone had experience splitting these wires out? He says he will "cut it just before it enters the fuse box"

Will this pose a significant problem? Not sure how much wiring is involved with the AC.

Re: Retrofitting AC

Posted: Fri Sep 17, 2021 7:30 am
by DanThe
There may be the same white 5 pin plug in the fusebox that the separate loom uses to connect up, get him to open up the fusebox and take some photos before hacking away randomly

Re: Retrofitting AC

Posted: Sat Sep 18, 2021 11:01 am
by BHadley
There is a wiki page on this retrofit in here also….

Re: Retrofitting AC

Posted: Sat Sep 18, 2021 12:11 pm
by onthames
BHadley wrote:
Sat Sep 18, 2021 11:01 am
There is a wiki page on this retrofit in here also….
It's rather vague for a newbie like me but should help

Re: Retrofitting AC

Posted: Sat Apr 27, 2024 7:10 pm
by MikkoR
I have a similar plan. I've got almost all the components, currently missing only the pressure switch and dryer. Also missing the wiring between heater matrix and pressure switc/compressor. Basically it is not too hard to build using the wiring diagram. But, in my compressor plug there are three wires going to the compressor. I would like to believe that one (black/red) is for the clutch, but which are the remainin two...?