Garagistic M30 Swap Guide- Air Conditioning

Air conditioning in an E30 serves more than just the purpose of keeping you cold. It is relatively rare in E30’s nowadays to have functioning air conditioning systems, let alone swapped E30’s to have working A/C. Most modders and racers will remove the AC to keep the weight of their car down, including swapped cars. This is understandable. However, in my mind, I wanted to execute a swap that had not only had the comfort, but functionality of a stock E30. Not to mention, having women in the car in the summer really helps having AC.


R134A Conversion:

While you’re at the A/C rebuild, you might as well convert to R134a. There are some advantages and disadvantages. Here are my points regarding R134a/R12.

1. R134a is cheaper to refill than R12. R12 is rare and very expensive to fill (couple hundred dollars by a shop) as opposed to buying $20 worth of refill cans at autozone/pepboys.

2. R12 is actually more efficient than R12, meaning that if you had the two systems in a side by side comparison, the R12 would actually blow colder than R134a. The way that you overcome this is to ether get a larger condenser or a better fan. While a condenser would be more effective, the fan is a relatively cheap and practical tradeoff. This is what I did.

3. To go to R134a, there are theories as to whether you should change out all of your seals and oil to R134a. While this has some merit and many have claimed no leaks without having changed any seals, it is definitely recommended. Especially if you have all of the tubing out of the car and can easily change them.

To upgrade to R134a, use the kit from autohausaz, click here. It’s approximately $32 and comes with all multiple sized O-Rings and the High/Low Pressure Inlets for the correct fittings. This does not come with the oil, which you do need to top off the compressor. See Figure 73.


The wiring of the E32/E34 compressor is exactly the same as in the E30 compressor. Just remove the wiring from the E30 compressor and adapt the plug for the E34 compressor. There are 2 wires to the compressor: Signal & Ground. These wires do not go through the Engine Wiring harness. They go through the E30 Body harness.


See below in Figure 74 for the E32 A/C compressor. These hookups differ from that of the E30 Compressor.