Retrofitting Aircon
Almost every modern car comes equipped with air-conditioning these days; a feature that you take for granted, until you step into an E30 and realise it's not there. To help you cool your sweaty brow, here's how to get your chill on in an E30.
Contents
Components
You will need the following parts to hand before you begin this installation. While many of these parts can be sourced from scrapyards and donor vehicles, we highly recommend purchasing new parts (*) in some cases.
- Aircon heater matrix containing evaporator with fitted expansion valve
- Aircon-compatible radiator with temperature sensor
- Condenser* and fan
- Compressor and bracket
- Receiver Drier*
- Pipework
- Aircon Loom
- O-rings (refer to realoem.com for part numbers and quantities)*
- Compressor Oil (PAG-46 for the standard BMW-Seiko unit, 8 fl. oz.)*
Installation
Installing Aircon is a very involved process. A large portion of the interior needs dismantling, as well as the process of leak detecting and charging the system once complete. We recommend allocating three days in total for this work.
Heater Matrix
The Heater Matrix, which contains the evaporator, is the most cumbersome part of the installation since you need to remove the dashboard to do it. So that we don't repeat ourselves, learn more about removing the dash here.
With the dash out, we need to drill some holes into the bulkhead from the drain pipes. The main hole is located on the transmission tunnel on the left hand side; curl back the carpet from around the foot air vents, and you should see an oval shape cut into the sound deadening. This is where the rubber drain hole needs to be:
There are two others as well, but if you have the heater matrix in place you'll see where the drain holes are supposed to be. BMW knocked dimples into the metal for later drilling, and the holes need to be 25mm.
Once the holes are in place, the heater matrix can be fitted in place. Don't reassemble the interior yet though; we still need to deal with the pipework.
Pipework
The rubber and metal pipework is what allows the refrigerant to circulate around the system. There are two main pipes; the supply and return from the engine bay into the cabin area to feed the heater matrix. Then there's the individual links between components within the engine bay.
To start with, lets look at getting those supply and return pipes through the bulkhead. BMW helped out by stamping a cut-out into the shell, and all you have to do is find it and knock it out with a hammer. It's located next to the battery tray, under the bonnet clamp. Remove that clamp, and tap around with a hammer until it pops out like so:
Then you can feed your pipes in and bolt them up to the evaporator within the matrix. Once that's done, you can go about fixing the pipework to its proper fittings inside the engine bay until it looks like this:
Note that one pipe runs under the inner wing "lip", while the other runs down the side of the suspension turret. They will meet up by the condenser and compressor, in this arrangement:
The pipework will also include the receiver drier. The receiver/drier slots into a circular hole in the metalwork just behind the headlight, so punch the blanking plate out and slip the unit in, then run the pipe back to the compressor.
Condenser and Fan
The condenser and fan mount in place in front of the existing vehicle radiator, which means you will have to remove the radiator to get to it. You'll also need to remove the plastic shroud that fits in front of the existing radiator, so it's best to disassemble some of the front grille so that you can see what you're doing.
With the area clear, you can feed in the condenser and fan. The assembly will bolt to the slam panel
Compressor
Next we move onto the compressor. First thing is to install the mounting bracket, which is bolted to the side of the block on the exhaust side, like so:
Then offer up the compressor with its adjuster bracket, and fit it loosely. Then you'll need to install and a new belt on the middle groove of the accessory belt pulley. Unfortunately this will mean removing one of the existing belts; if you're not sure how to do that, learn more about changing belts.
Receiver Drier
The receiver drier is mounted within the pipework, and is a sealed unit. It bolts to the car body by the compressor.
If you are fitting a second-hand system and do not know the age of the receiver drier, then it is heavily recommended to purchase a new component since these parts are so sensitive to moisture.
Wiring
Two different types of factory fit aircon loom exist. One type is basically separate from the rest of the engine bay loom, and is relatively simple to remove and reinstall. There's a small 5 pin connector inside the fusebox, and a few fuse and relay terminals that need to be clipped into the fusebox.
The second type is physically part of the main engine bay loom, and cannot easily be split from the main loom. It's also wired through into the car, and does not have the 5 pin connector inside the fusebox. It's certainly still possible to use this version, but it's a bit more involved.
With either type, there is no work involved under the dash. BMW were good in the fact that they ran the extra wires from the heater box connector through into the fusebox. All you need to do inside the car, is plug the aircon heater box wiring into the standard connector, and you're done. There's also a single wire that needs connecting into the engine loom (under the dash). This is what tells the ECU to increase the idle speed when you switch the A/C on.
For the fuse crimps, you first need to remove the plastic locking strips, or you will never get them out of the donor vehicle. Once this is removed, they will come out quite easily with the aid of a small jewellers screwdriver. Just push it down the side of the crimp (from the top), and wiggle the wire underneath, and it should come out. Don't force it, or you will damage the crimp (not the end of the world, as you can get replacements).
There should also be a small diode connected to a single wire (possibly the violet/black one you can see in the photo above). It's fitted inside a black plastic housing that has a spade terminal on each end. This needs to go with the aircon loom.
Once you have the wiring to hand, it should look like this:
To reinstall, you need to open up your own Fuse Box and feed those wires into it, according to their positions in the pictures below:
To confirm these wires:
- Thick Black/Green is Fuse 3
- Thick Black/Blue is Fuse 18
- The two small black wires in the space on Relay K1
- The small Brown wire (earth) in the space on Relay K6
- The small Brown/Black wire in the space on Relay K6
You will also need to connect the open end of the diode to the the clear spade connector (brown looking plug). This stops the aircon switching on when the fan hits slow speed with engine temps triggering the low fan speed with AC off. Don't forget to earth the loom at the nearside headlamp earthing post.
You will also be left with this black connector, which comes off the loom near the Aircon Switch:
It plugs into a special connector next to the main engine ECU, which sits under the instrument cluster on RHD cars. Pop off the knee panel under the steering column and you'll see the ECU and connector easily enough.
