I have decided to document my install of the Classic Retrofit Electrocooler system into my 81 SC. A couple of disclaimers: I am not a mechanic. I'm a guy with 3 kids with a garage and a basic set of tools. I have no idea if my install will be successful, or how long it will take. I may be doing things the wrong way sometimes, so if anyone sees something that doesn't look right then please let me know. I will not be offended.

My SC was a factory AC car. When I bought it, I knew that the AC didn't work. I wasn't sure that I needed it, but after driving late last summer and fall I realized that it would be nice to have AC. I needed a bunch of work over the winter, so I had the independent that I use remove the factory AC components and lines. They also upgraded the alternator to a 90A unit as required. I ended up buying a new fan housing instead of having the stock one machined to fit the new alternator. I considered having the shop do the install, but the labor cost involved would have been very costly.

I read the directions a bunch of times and tried to get an idea of where everything goes, but it became apparent that I was just going to have to dig in and figure it out as I went.

Unfortunately, I can only work on the car an hour or two here or there when the kids are in bed or everyone is out of the house. I currently have about 8.5 hours into the install over 3 nights. I have never worked on the car before so I'm sure someone with experience will go much faster. I'm also doing a fair amount of cleaning as I go.

Finished in Irish Green, this LHD 912 spent its early life overseas. It was imported into the UK in September 2000 and used surprisingly sparingly, covering fewer than 3,000 miles in twenty years.

In early 2020, it was sent to our friend Jez Parsons at Carrera Performance in Horsham for an engine rebuild and general recommissioning. While the car was in the workshop, Jez also fitted our upgraded alternator and the full Electrocooler air conditioning package. The car also had some modern lighting fitted, so hopefully should now be seeing more use than it has seen in the last two decades.

Great to see classics as pretty as this one being used on UK roads. We definitely need to see more of this and fitting modern air conditioning is a great way to increase the motivation to use your classic regularly!

Given the lack of space in the car, we had to move a few parts. The original heater unit was removed. The electric A/C compressor was mounted in the boot/trunk. The condenser went behind the engine grille and the oil filter was moved to leave space for the fans.

The complete installation was achieved with just two small holes added to the rear bulkhead.

My car is a 1966 911 SWB. There's no fan lever on the dashboard, but where will I be able to adjust the airflow?

Jonny's answer:

The ’66 SWB will require some modification for installation but it has been done before. Have a look at this news item:

https://www.classicretrofit.com/blogs/news/how-to-install-electric-air-conditioning-in-a-1967-porsche-911-swb

For a short-wheelbase 911, the main points are as follows:

1) The cowl stay must be removed

2) The area under the hood inlet needs to be modified to work with the blower inlet

3) Holes are required in the bulkhead to let air in and out of the car

4) a switch is needed to operate the fan

5) Vents are required (suggest under the dash and clock position)

I've begun discussion with Johnny from Classic Retrofit about putting an order together for the electro cooler AC kit. I had been kind of hanging back to see other people install it in hot temps like FL but I think I'm ready to move forward.

I have begun my installation. Thus far I have removed my front valence as I am opting to install a RUF style spoiler so that I can avoid having to trim the fog light bracket on my factory valance. I also have installed both the condenser and drier. I will continue to provide updates as I progress.

I chose to buy a RUF style front spoiler to replace my stock valence to avoid cutting the fog light bracket, and have a non-functional fog light. Since the RUF spoiler sits further way than the stock spoiler I was able to install the fog lights without trimming the headlight. I realize it’s more money, but I wanted to avoid permanently modifying the stock valence.

In regards to the current setup requiring the removal of the stock washer tank, you obviously wouldn’t have to do it if you installed the fenderwell condenser in the rear fender. However, that would entail running a long run of a/c hose similar to the original setup the full length of the car, but also would not be ideal for purposes of cooling. I was happy to lose the 30lbs of dead weight from my front fender, and didn’t have a problem replumbing the 2 windshield systems along with the headlight washers using the stock intensive windshield washer reservoir located in the frunk. (CR: note that we now offer our 911 washer tank upgrade to solve the problem/weight of the large washer tank).

I traded numerous emails with Jonny to further clarify my understanding of the directions, and he has been nothing short of fantastic. A couple of things to mention (CR: since corrected at our end), I had to shorten the horseshoe strap by an inch on the tub side as it interfered with the the twist on the factory bracket, and I also had to drill a new hole in the strap at the correct level to align with the existing threaded hole in the tub.

I also had to adjust the angle of the bracket that holds the drier so that it doesn't make direct contact against the condenser fins. I still need to install a piece of the foam padding provided between the drier and condenser, but I will save this for when I install the hoses and make the final fit adjustments.

I should have my install done this coming week. I have all the new a/c lines run and connected along with the on/off switch, along with the drier, fenderwell condenser and cabin hoses. All that remains are installing the hoses in the trunk.

Although it took me a long time to complete my install, that is not a reflection upon the product, nor the installation instructions, but rather other activities competing for my time. I have also taken the time to replace my side and center vents as the foam on the flaps had long ago dry rotted. After placing an order for new ones, I played around with the old vents and I was successful at fully disassembling them, and I plan to replace the foam with rubber and either keep them as a spare, or list for sale.

I decided to mount my on/off switch in my center console, and chose to create a custom insert to house the switch, emergency flasher, rear window defroster, voltmeter and AFR gauge.

After I finished my install, and following running the tests I took it out for a spin to see the initial results. Ambient temps have cooled off to a mild 88F with 44% humidity, unlike the 100+ temps with 80% humidity we have experienced up until yesterday’s. My vent temps ranged from 39F to 45F with the fan set to setting II.

Prior to the test trip, my car had been parked in my garage, so there was no sun heat sink. While I have the upgraded alternator, the battery wasn’t fully charged as it has been off the road for 8 months, and had been drained by my having been working on the install of the unit. I decided to test again once temps had gone back up, and I had run the car long enough to fully recharge the system. Thus far I am very pleased with the results.

Day 2 - temps remain in the upper 80s, and are scheduled to stay there for the next week (doesn´t it figure that when I want it hot, it won´t live up to what is normal weather for this time of year). Interior temp prior to turning on the A/C was about 89F with relative low humidity. After about 5 minutes the cabin temperature was about 78F, and vent temp of 43F.  Like yesterday, the lowest vent temp was just below 40F. Using the high output alternator, the voltage with the a/c off it was 14.1+ volts, and with it switched on it rarely went below 13.9 volts. The only electrical items operating the entire time was the radio, otherwise with the a/c on, it was the compressor and fans.

While with the windows down and a/c off it wasn´t a bad day, with the windows up and a/c on it was very comfortable.

Points to consider:

For those of you awaiting the arrival of your new a/c system, you may want to consider making decisions on the following items:
1) fog lights - whether to trim the supporting bracket on your factory valance and gut the fog light (Jonny indicates that he will be coming up with an alternative to re-activate it at a later time) versus doing as I am doing by getting an aftermarket spoiler that pushes the fog lighrs further forward in order to not interfere with the new condenser. I you go the same route I have allow enough time to receive it, get it test fitted and have it painted.

2) push button placement - make your decision as to whether you are going to install it in your dash or in a center console (if you have one). I decided to mount it in the center console since the existing dials become useless once you implement the new solution. I decided to remove the bracket containing the 2 a/c dials and replace it with a gauge panel sold by 9xauto.com (actually bought 2, 1 that is blank, and another containing a voltmeter). If you aren't needing your existing a/c you can begin the removal of the existing center console buttons and getting your replacement panels in hand.

3) prep for compressor installation - if you decide to install the compressor in the smuggler's box, you may want to consider getting a replacement lid that has holes in it for added venting. While Jonny has indicated that no additional cooling for the compressor is required, I decided it couldn't hurt to provide a means of heat to escape the otherwise enclosed area. If you go this route you can take care of it in advance.

4) windshield washer - you will need an alternative to the large wheel well tank in order to provide space for the new condenser (CR: we now offer the 911 washer tank kit). Doing so will allow you to clean the wheel well area in preparation for your condenser install. I already had the secondary booster bottle option in my trunk, so I chose to re-plumb my system so that all 3 systems (headlight, regular windshield and intense wash) continue to function regardless of the fact that I only use the regular windshield washer function. There are some good posts on this site that help you understand the plumbing.

Since I wasn't using my old a/c system I moved forward with the removal of all my existing components prior to having received my new system.

Jonny, I tested fitted a blower on my '87 930 after removing the old blower and ducts but before adding new T pieces and ducts. Unfortunately the new blower won't fit!! It seems the older 911's has fewer wiring and electrical components on the cabin wall. Here's a photo of the trunk of my car showing the problem area. Am I required to relocate the electrical components further out of the way? I'm not sure how far they can be moved. Do you know anyone who installed the blower on a later model air cooled 911 or 930? If yes then how was the blower installed?

I have been doing the install on the blue car for the new owner, and the "T" junction on the drivers side was a definite frustration, the crux of the install so far for sure.. My fingers were also cut and I don't know how exactly. I got all the ducting in and situated but it will be coming back out tomorrow for the 5th or 6th time now. I am pretty happy with the ducting and will tackle the hoses tomorrow. I am not using the fresh air slide controls, so I made some tabs that will hold the blend valves open right in the middle. I already had the fan wired to a 2 way toggle switch, but will change that to a 3 way toggle switch. I completely ditched the factory style hose for some heat/defrost hose from NAPA, it is much easier to work with.

Consider user survey

This keen home installer was amongst one of our first A/C customers. He took the time to conceal as many wires as possible, creating a very nice finish.

I was attempting to put the condenser fittings on the condenser and I have an issue, the o-ring side of the fitting appears to be bottoming out in the condenser before the flange plate seat flat on its location about .03/.04 ( 1 mm). Do I put a shim under the flange to compensate, take material off the o-ring side so everything seats or replace fitting I’m worried about the o-ring location lining up

CR:  Is it going in ‘square’?  find you have to hold it whilst tightening the screw.

Yes it’s going in square. I thought the same so I took the o-ring off to investigate and the fittings bottom out prior to the flange plate seating on the boss of the condenser so I don’t believe it’s an assembly problem. I think the post is either too long or the bores too shallow, I don’t have my micrometers here to verify.

CR: I don’t think the flange seating is is critical as long as the fitting body itself is square. The o ring does the work. You could put a washer under the screw head if you want it to look right. There is some variance on the condensers as they are made by a few different manufacturers. It’s a Boxster condenser in case you wondered.

A few wiring questions. Can I hook the hot leads on the wiring looms to the four positions on your fuse panel that are always hot and where do the ambient and cabin sensors go? Do the three blue wires tie in to the wire from that back of the defrost? it looks like that is what the wiring diagram is inferring.

CR: 12v on any blue wire will cause the compressor to run slow. The best thing to do is to test the wire you want to connect to with a voltmeter. E.g. defog function. You don’t want the system to always run slow, just when the defog is on. If you have our upgraded alternator, you don’t need to connect any of the blue wires.

OK I have the upgraded alternator so thank you. I can’t get power to the switch, I hooked it up to power under the dash and then directly to fuse panel but no does not illuminate, the blower works using the slide controls but I cannot get the button to work: maybe it’s defective, I don’t know.

CR: You have to start the engine for the switch to light up. The ECU monitors the voltage. It must be above 12.6 for the switch to light.

I got everything hooked up the button works with the car at idle , however it only appears that the fan is running at one speed? Let me know what you think.

CR: The cabin blower fan is controlled by the original sliders in the car. Did these work with the original fresh air blower? This circuit is completely independent from the other ECU wiring etc. Make sure you don’t install the plug in our blower the wrong way. The plug cable must come up from the bottom as per the instruction manual.

I guess I misunderstood the instructions. I thought the LED controlled the fan speed as well. I have adequate fan speed with the levers through the clock vent, the other lower vents not as much. I probably won’t charge the system until I get the car out this spring: I need to put the carpet in and the rest of the upholstery before I can take it to be charged, the compressor seems to be cycling as well, so I think everything is good for now.