KNOWLEDGE: Early S30 JDM Factory and aftermarket Air Conditioner

Many 240Z which are from USA come with an air conditioning system installed. After reading a few times in the local Z-chats that imported cars from USA came equipped with “factory air conditioning”, i thought it’s about time to share some deeper insights on this topic, and get some things straight.

Disclaimer
As with all my knowledge articles, i tried my best to get all information from trustworthy and official sources. However, i cannot guarantee that all information is 100% correct. If you have any correction, input or additional information, i appreciate if you let me know. I’ll update this post whenever i find something to add or change. I am not a professional journalist and i put countless unpaid hours of work and years of research into this post and spent quite a bit of money to source a lot of original documents, so please ask, before you copy anything. Thanks!

1. Introduction:
So, was there a factory developed / installed air conditioning system for the early S30 chassis?
Simple answer: Yes, but not all models / markets got it (See details in next chapter):

According to the Nissan “service shuho” bulletin “Fairlady Z introduction”, it was a completely new developed “high performance” and “compact” system for the S30 car, which added additional cooling to the regular heater / blower setup and utilized the three standard air ventilation outlets of the S30 cars.

“The S30 is the first sports car to feature an air conditioning system, which is rarely found in other cars in the same class, both domestically and internationally. This allows the S30 to be used as both sports car and a luxury grand touring car.”

According to the same introduction bulletin, most of the system is built into the center console, which makes it a “built-in” type which doesn’t reduce trunk space as with the (back then) conventional trunk-installed coolers, nor does it distrupt comfort or safety of the front seats as with the dash-installed coolers.
Additionally, the engines negative pressure is used to operate the valves and actuators, making operation easy. According to that bulletin, this system was first used in Nissan vehiclas and has until then not been adopted by any other manufacturer in a similar class vehicle worldwide.

2. Which markets / cars got  the OEM HVAC?
1. There was a factory installed HVAC on japanese market S30-C cars and the same A/C as dealer-installed option for all other japanese market S30 Fairlady Z Cars, except the PS30 (= Z432) variants.
2. Until the introduction September 1974 (on the 260Z), a nissan factory HVAC (Heating, Ventilation and Air Conditioning) was never installed on export market Datsun 240Zs

The system was only designed for the RHD chassis, but to my knowledge never was sold outside of Japan. So this means it was only ever available from production cars with the designation code S30-C or as an option for all other RHD S30 cars (except the PS30 variants) in Japan.
The LHD cars never came with the installation points, holes, etc required to install it. Hence it’s also not possible to install a JDM factory HVAC system on an (LHD) export car without extensive additional modifications.
Also for Australia and UK, where it would have been a simple addon taken from the JDM cars, it was never available, to my knowledge, despite being RHD markets and particularly australia being a hot country.
But why do we see so many non-japanese 240Z cars with HVAC installed? Short answer. They’re aftermarket, often dealer installed Airconditioning systems. We’ll get to those in a minute.

Interestingly, the A/C option is never pictured, prominently mentioned and only shown in a small options table in only two of the four original Japanese market sales brochures which i have.
(Blue dots = options, yellow marked column = air conditioning system)

The A/C system can not be found in USA, Australian or european Parts manuals until september 1974, as shown below in the Australian spec parts manual michrofiches:

I couldn’t find any service instructions or photos in my Japanese 1971 service manual, but instead there was a special Japanese 1970 “Fairlady Z Air conditionier installation manual” which Kats shared a while ago on ClassicZcars.com

3. How does it work?
Compared to the standard heater / blower setup and the according controls, as shown below (from the 1970 USDM 240 operation manual), where you can select the outlet vents, the heater temperature and amount of heat added to the ventilation….

… the controls on the HVAC equipped cars look similar, but are slightly different, with the added possibility to select cooling / cold as well:

Without going into too great technical details, here’s a simple overview of the different airflow possibilities from the service introduction bulletin:

 

4. What parts does it consist of?
Going through the japanese part list the HVAC section consists of 146 parts positions (including all fasteners, etc) required for the HVAC installation.

The installation manal by Kats shown below (and loosely translated by google), explains the individual parts in nice detail and adds some context.


You can also see the full HVAC setup in the first picture of this Post, from the Japanese Fairlady Z introduction Bulletin.
Individual Part numbers can be found in the Japanese Parts manual catalogues:

I’d like to point out the different front springs that were used with cars that came with airc onditioning installed (see highlighted yellow in the previous picture). Most probably due to the added weight of the system in the front section of the car:

The main difference to the standard heater / blower setup, is of course the added cooler / compressor system. When translating the japanese manual, the output was “refridgirator” because that’s basically what it is. A special coolant fluid is compressed in the compressor and expanded in an evaporator and then cools down the air in the heater core.

Another noteworthy Part is the F.I.C.D, which stands for “Fast Idle Control Device”, see yellow area highlighted in the second picture below.
According to the manual, it was a common issue for cars equipped with air conditioning to overheat when standing still with idling motor, due to the added power-requirement of the compressor, etc.
To prevent overheating, the FICD (as the name suggests) automatically raises the standard idling speed from 700 to 800 rpm when standing still. The system was controlled by a vacuum controlled FICD Air valve.
If the pressure in t he cooling fluid is too low, a pressure switch in the evaporator will activate the magnetic clutch at the compressor to increase the pressure and at the same time activate a magnetic valve in the Intake manifold to create an underpressure to the FICD which then increases the idle speed.

I’m still looking for a good photo of the actual system inside or outiside an Fairlady Z. So if you have good photos, please feel free to share them with me.

The Japanese introduction bulletin goes pretty deep into detail and even shows the wiring diagram:

Even going as far as showing the whole specification of all components (loosely translated here with google):

Update: I got this October 1974 Service bulletn “Hints on servicing the Nissan Air conditioner”. which is not car specific, but shows again some details of the A/C systems used in Nissan cars.

Here the brands of the S30 Export market (I guess 260Z and 280Z only) Brand of A/C are mentioned: Hitachi both for LHD and RHD cars:

5. Datsun USA Dealer installed HVAC system
I’m not sure if A.R.A. developed this on their own, upon requests of datsun dealers in the USA or if it was on request by datsun USA themselves, but either way, A.R.A. offered a 240Z “custom” air conditioning system for the 240Z in the USA.
The below installation manual from A.R.A was shared by user Zed2 on Classiczcars.com

The kit was eventuelly also offered as a dealer-installed option by Datsun USA. As this 1972 Datsun accessories catalogue (originally from Zhome.com) shows.
The Part No 99990-00216 indicates that this is not a part offered from the factory in Japan, but a local US-market only part number.
Note the additional thermostat control knob, installed in a small pod below the steering wheel:

Datsun USA even created an owners manual / warranty card, which was (sometimes?) provided alongside the original A.R.A. operating manual. Pictures from JDM-Car-Parts.com where you still can buy those original ones:

In that Manual, you can also see how the system is controlled:

Another commom solution back in the days seems to be the “Frigiking” brand A/C. It looks pretty similar to that of A.R.A with the additional pod with the rotary knob at the drivers knee. According to some online comments, these were also often installed by Datsun dealerships.
See below catalogue pages which i found on Datsun1200.com

6. Other Aftermarket options
Over the years, plenty of different systems were available and installed in the various S30 platform cars, some more, some less plug-and-play.
From many homemade hack-jobs (some of which have become fairly common swaps) to broadly (innofficially) USA dealer-installed HVAC sytems.

I think one of the most common otions these days is the Vintage Air Gen II Mini: https://www.godzillaraceworks.com/hvac/vintageairminiii, which is still available as a pretty modern and powerful aftermarket solution.

I won’t go and list every model / type that was ever installed on 240Z’s, but if you have good catalogue scans of any 240Z specific designed, please feel free to s hare them with me so i can post them here.
Here’s another example of an aftermaket A/C control pod, that was attached to the side of the center console and has some OEM look a like texture. (source)

Another modern retro look aftermarket HVAC from Japan is the Kameari Engine Works “Cooler Kit” for the Z, which is also sold via Starroad, etc and available for different cars. Kameari also sells individual compressors etc so you can build your own kit.

7. OEM Swaps
An natural questions which comes up here is, if the 260Z, 280Z or any later models A/C system will fit plug-and-play into the 240Z? I haven’t really researched it, but it appears that it is possible with some modifications, mainly consisting of OEM parts. However don’t rely on this information. I’m sure you can find plenty of details in the depths of the interwebs and the usual specialist forums. My guess is also that the later models systems have some improvements and are slightly simplified, lighter and smaller, compared to this very first factory attempts.

8. Conclusion:
It is kind of strange that Nissan Motor Co. put a lot of effort in developing and manufacturing a “modern” and integrated air conditioning system, but then only sold it for the RHD cars and local markets, despite the fact that the car was sold in big hot markets like Australia and USA. It seems like even in the japanese Market NMC didn’t make a lot of noise about their new fancy A/C system and didn’t really actively promote it and instead focused their advertizing on the superb engine, suspension, steering, etc.
I don’t know the reasons, but either they were not really confident about their product themselves or the state of it’s development. Or they simply thought it would not fit the concept of the sporty S30 to add more weight and luxurey grand tourer features, or they thought most people would not be interested in it anyway.
Either way, they did most probably not sell a lot of those in Japan and i wonder how many cars were actually equipped with the factory A/C. These days it’s hard to find the parts or even a complete set and if so it usually comes at a premium price.
With A/C becoming a standard in many cars in the mid 70ies, Nissan quickly realized the potential and made sure the next generation 260Z and later models came with an A/C standard, or option for all markets.

9. Special thanks
goes out to Katsuhiko Endo, Florian Steinl, Krisztian Koczis and all the others – who either contributed directly to this article, or over the years released some of the important puzzle pieces which made this article possible.