A/C installation from scratch

[Robert Bondi]

I'm curious if anyone's done this before? Not repairing the A/C, but installing a system in a car that has none.....
I'm moving this project up on my Euro restoration car (77 528) because the car is otherwise generally unusable in my Texas climate.
I'm dividing my installation into three stages as my restoration is being done one major project at a time with some driving
in between.

Stage 1 (in progress): Switch to U.S. center console and install the blower box with a new fan. I call it U.S. as the donor car is for these parts - clearly the center console front and side panels are different for A/C cars. Even the extra fan will help before A/C is actually in. As I just had all the carpet out, I took the time to drill three new holes for later: condensate drain and the hi-side/low-side lines behind the glove box to the engine bay. Fortunately, I was able to precisely place these using measurements from my 530i. I'm cleaning up a donor blower box from a 79 E24 (E28 box also interchangeable, or at least from 84 528e). Latest headache here is discovering the need for peripheral parts, notably the base plate and the "covering piece" which is duct work.

https://www.realoem.com/bmw/enUS/showpa ... Id=64_0361

The base plate is shared with E28 and E24, so I can probably locate used. I expect a bit of fabrication need to close the gap for the covering piece.

Stage 2: A/C components in the interior, namely the evaporator and expansion valve. I have these new for the E28 and will be going that route of aluminum lines and o-rings. I'm probably also buying a bender for aluminum tubing.

Stage 3: Everything in the engine bay. Relatively easier for me since I did all this in converting my 530i to R134a...There's also
more room out there to customize and I can leverage various A/C kits and parts from other M30 cars. I already got the compressor stuff here since it's direct application for us with that nice bracket from our E28 friends: https://www.acsolutions.co/

There's a little bit of light wiring to navigate in all this as well.

I'll drop some pictures later.

Robert

[Mike W.]

I did it on a Bavaria long ago. Pretty straightforward except I neglected to do the evaporator drain hole. A few weeks after installation I heard this sound of water hitting a fan. Then soon I got some splashing up on my feet. Ooops. Not wanting to R and R the whole thing I improvised, which worked well for the next 100K or so until it was rear ended and totaled. I should say the improvised drain worked well, the Bav A/C as weak even after I replaced the old square York compressor with a E12 era swashplate one, it had a smaller blower and housing than E12s.

It's definitely doable. A bit of a challenge drilling the holes in the firewall for the lines, but again, doable. I may have that base mounting plate if it's the same as E28s, shoot me your email and I'll send a pic off.

[Robert Bondi]

Hi Mike,
PM sent. Thanks for sharing...that's encouraging. My hole saws went through the firewall surpisingly easy and I was working from the inside. Deciding exactly where to drill them was a bit of worry...

Robert

I did it on a Bavaria long ago. Pretty straightforward except I neglected to do the evaporator drain hole. A few weeks after installation I heard this sound of water hitting a fan. Then soon I got some splashing up on my feet. Ooops. Not wanting to R and R the whole thing I improvised, which worked well for the next 100K or so until it was rear ended and totaled. I should say the improvised drain worked well, the Bav A/C as weak even after I replaced the old square York compressor with a E12 era swashplate one, it had a smaller blower and housing than E12s.

It's definitely doable. A bit of a challenge drilling the holes in the firewall for the lines, but again, doable. I may have that base mounting plate if it's the same as E28s, shoot me your email and I'll send a pic off.

[Robert Bondi]

Some picture updates...

I scored the base plate for the evaporator box. It supposedly from an 84 528e. One problem solved. You can also see the
condensate drain in the center.



Here's the duct work blank plate off my non-AC car. Presumably, this is just removed and the "covering piece" is swapped
in to take the output of the evaporator blower box. I expect I'll be creating something out of plastic and flexible duct work.
Surprisingly, this plate is just held in by 3 of those Christmas tree type nylon fasteners so common on modern cars. Fortunately, the E12
has very few of these.

[0257]

Have not tried to install a complete system on an e12, but I did install an ICE Air kit on my 2002tii, which never had a/c before I bought it. You have already identified the scariest part of the job, which is drilling through the firewall. Measure again and again for about a month, then drill once! Obviously your ac car can give you some guidance as to where to put those holes, but it’s still hair-raising. Watch out for brake lines and wires!

Finding all the parts is the next most daunting task, which is why i bought the available kit. Did not have the courage of my convictions. Might do it piecemail if I had it to do over again. Good luck with that part.

In fat, as you know, that’s what I’m doing now on my 528i. Have the acsolutions bracket and a Sanden, and have located a 17x19 parallel flow condensor at Vintage Air just up the road from you which I think will fit the apron opening just about right. Still searching for the right drier.

Also thinking about how to upgrade the anemic blower and evaporator. Spent a good part of today getting the evaporator box exposed for removal and will pluck it tomorrow. Looking at the blower fan, i’m not sure it’s not even smaller than the e9 fan. That said, there seems to be enough room under the dash for a bigger unit, like your e28 box. Also, it looks like it may be possible to put an e28 fan in the e12 box. I have what I think is an e28 box and will try to test fit it. Has a much bigger hamster wheels than my e12 unit; also, the info I’m getting from various vendors indicates the bigger e28 fan may fit in the e12 box. I know you have mix and match parts as well, and may be trying similar. So, much experimentation coming up in the next weeks. Will follow this thread with interest. Good luck to us!

[Robert Bondi]

I've finally shifted my focus back to the AC installation on the Euro restoration car. Talking with Ken (0257) back and forth on the refresh of his AC system over the last year helped me plan and solidify what needs to be done. The interior really boils down to acquiring/rebuilding these three components:

1. Climate control panel
2. Heater core enclosure box
3. Evaporator box

Then, there's a little bit of wiring and the hard line plumbing for the evaporator. Holes for the evap lines and the condensate drain were already made well over a year ago.

I recently rebuilt the climate control panel. I elected to keep the nice panel in German from the 528. I stripped it down to bare panel with the illumination back plate and then had several used climate panels from US A/C cars for the extra parts. The FAQ on the rotary switch is a good reference here. Aside from reassembly and the cleaning and lubrication of parts, I converted the non-A/C Euro panel into an A/C ready climate panel with these 5 additions:

1. thermostat switch and capillary probe line (Ranco)
2. 5 terminal relay (BMW 61311243086, Bosch 0332204402)
3. microswitch (Burgess GVBF6)
4. plastic crescent cam that slides onto the AC dial knob - this actuates the microswitch
5. 4 additional A/C fan contacts needed to be populated on bottom of the rotary switch

I couldn't make sense of all the numbering on the Ranco switch to identify what is actually the part number buried in other information. The microswitch is actually fairly generic...I recently replaced a switch just like it for my microwave door not long ago.

Front of the Euro climate control panel. Note the P/N last 7 digits on the climate panel harness on the left....NLA of course. One of my used US panels had most of this harness present, so great opportunity to splice into existing wiring and label my work.


Back of climate control panel during reassembly


Back of climate control panel after reassembly and labeling/identification of all wires


I'm now rebuilding the heater core enclosure, which is likely the next thread update.

[Robert Bondi]

Heater core enclosure now rebuilt and installed. I had acquired a used box from a 79 528i to rebuild on the bench and swap in. This component was fairly straight-forward. I took everything apart, cleaned it, and lubricated moving parts. The heater fan motor was new as of 2018 and reused. New parts included a heater core from Walloth and Nesch, NOS heater water valve, and a new resistor cage. All foam replaced. Highlight pictures:

Carefully splitting the box apart and revealing cleaning opportunities.


Close-up of new heater water valve.


Newly foamed vent flaps and sizing up heater core for install. Unlike the old Behr unit, this earlier? design has no nylon side tanks and appears to be all brass. Only downside is support attachment point for input brass pipe also missing, so we'll install a custom support solution.


New heater/vent fan resistor cage


Custom support aluminum bracket and nylon standoff for brass input pipe


Pressure testing the heater core.


Views of the rebuilt heater core enclosure before install. Red gasket is silicone foam.

[528i-1981]

Neat and fastidious work as always, Robert. Have you mounted the compressor and all the lines yet?

PS. We see the Spal fan box in the background.

[Robert Bondi]

Hey Eric. Not yet, but getting there.... My strategy is doing all the interior work as the first phase of the project. I'm currently bending the aluminum hard lines going through the firewall. The second phase of the AC will be doing all the work in the engine bay beyond the receiver/drier. I'm almost done with the evaporator box and will post some of those highlights.

Neat and fastidious work as always, Robert. Have you mounted the compressor and all the lines yet?

PS. We see the Spal fan box in the background.