Retrofitting AC

[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.

[twenty]

Barry @ BMR Performance is your man. I believe he's done quite a few conversions and retrofits.

[onthames]

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!

[flybynite]

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.

[onthames]

Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!

[flybynite]

Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!

Found it

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

[onthames]

Well changing the compressor is out of the question I think. The pipes look good. I'll try find that thread. Cheers!

Found it

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!

[Cloggy Saint]

When I converted from R12 to R134a I kept the original compressor and it all works fine.

[onthames]

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

[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!

[onthames]

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.

[Cloggy Saint]

If it was done by the book it would have a R134a sticker on/around the right hand turret.

[Tzantushka]

*raises hand*
Yep - converted a R12 system to R134a last year.
You'll see more detail here

[onthames]

*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"

[flybynite]

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.

[onthames]

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

[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.

[onthames]

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.

[flybynite]

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

[onthames]

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

[flybynite]

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.

[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.

[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?

[onthames]

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

[Cloggy Saint]

My lhd ecu is above the glove box so that's probably the same too.

[onthames]

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.

[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.

[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

[BHadley]

There is a wiki page on this retrofit in here also….

[onthames]

There is a wiki page on this retrofit in here also….

It's rather vague for a newbie like me but should help

[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...?