https://classic-retrofit.com/forum/index.php?/discover/Classic Retrofit Product Support Forums - All ActivityenNew pump different assembly A number of years ago we moved over to a slightly different pump to as shown. We still use the same brackets however the spacers are slightly different. There is notches for the compressor ports in the side cheek brackets. first ensure these are the correct way around. Working from left to right, The large m8 bolt goes through the metal cheek first with a plastic washer between the head and the metal. Then between the metal and the pump goes the 15mm spacer. Dependent on kit this will either be 3 small plastic washers and a medium spacer or a single 15mm spacer. Once spacers are on and the bolts are pressed through the pump you can thread on the threaded cylinders. Offer up the left side cheek followed by the smaller m8 bolts with plastic washer between head and the metal. Everything should now be as per earlier instructionsWed, 09 Sep 2026 09:25:52 +0000New pump different assembly A number of years ago we moved over to a slightly different pump to as shown. We still use the same brackets however the spacers are slightly different. There is notches for the compressor ports in the side cheek brackets. first ensure these are the correct way around. Working from right to left, The large m8 bolt goes through the metal cheek first with a plastic washer between the head and the metal. Then between the metal and the pump goes the 15mm spacer. Dependent on kit this will either be 3 small plastic washers and a medium spacer or a single 15mm spacer. Once spacers are on and the bolts are pressed through the pump you can thread on the threaded cylinders. Offer up the left side cheek followed by the smaller m8 bolts with plastic washer between head and the metal. Following this you can assemble it to the base and add the relay bracket. Dependent of kit generation you will either have m5 bolts with nuts or m6 bolts direct into metal. Once you add the relay bracket you can then wire the pump to the Heavy duty contact relay, and then fit this relay to the bracket.Tue, 08 Sep 2026 12:21:37 +0000Clock vent The Round clock vent instals in place of the original clock. You will need to transfer over the original Rubber donut to the new vent, Depending on the condition of the donut and the vinyl on the dash, You may need to add additional tape/foam between the vent and the donut to ensure it fits correctly. Round Vent for 911 Clock Position. – Classic RetrofitMon, 07 Sep 2026 16:57:47 +0000Alternative button We often get asked about changing to a different button, This is something we have accommodated for within the ECU as we appreciate people would like to make the kit suit the rest of their build. By default the kit comes with a 'Smart switch' which in short is a momentary backlight toggle switch. If choosing an alternative 2 things to consider, Is it momentary or latching, and does it have a internal LED? The ECU needs 12V on the black/white wire to switch AC on. 12v on our loom is provided on the red wire. If the ECU button mode is set to Momentary, then a pulse is expected. If the ECU button mode is set to Latch then a Constant high level is expected. You can change this in ECU by typing BUT=0 or BUT=1. Use LIST to verify changes. For the Back lighting you will find a brown/yellow wire. This is a high side output to LED. You will need to experiment with LED/Resistor combination here. Here you can see a Snowflake knob added along side the typical location for screen, lights and cigarette lighter. Another example is , 'Austria3 a Classic retrofit customer repurposed an original switch and created a bespoke knob in his car.Mon, 07 Sep 2026 16:55:05 +0000Tue, 25 Aug 2026 15:33:41 +0000Thank you for your advice! I will get the data logger and check the temperature as you advised me. Regards,Tue, 11 Aug 2026 13:52:54 +0000Hi piejesu, Thanks for the tips! Before replacing the compressor, I suggest checking the refrigerant temperature at the condenser outlet. Ideally, it should be around 50°C (122°F); it loses efficiency above 60°C (140°F). I recommend using a wireless data logger to monitor this during drives. This Bluetooth sensor lets you track data on your phone: https://amzn.asia/d/0bc6s7EQ Good luck with your setup!Tue, 11 Aug 2026 07:43:48 +0000I also live in Japan and am suffering from this terrible summer heat. I installed an electric air cooler system (non Classic-Retrofit) in my vintage Alfa Romeo, but it hasn't been as effective as I had hoped, so I am looking for ways to improve it. After reading your post, I was truly amazed at the high level of cooling performance you’ve achieved with the electric cooling system. If there are any tricks to it, I would greatly appreciate your advice. For example, “dual-condensers are mandatory for this result” or “the Classic-Retrofit’s Compressor offers vastly superior performance compared to those from other manufacturers, so you have to replace the compressor at first”, etc.Mon, 10 Aug 2026 23:48:48 +0000Here is a snapshot of my engine bay. As you can see, it looks completely stock! The beauty of this system is that it's a 100% "stealth" upgrade. There are no visible fans, no altered aesthetics, and absolutely zero modification to the chassis—just pure modern performance hidden inside. You'd never guess it could beat 36°C (97°F) heat just by looking at it!Fri, 07 Aug 2026 16:01:05 +0000Fri, 07 Aug 2026 15:16:10 +0000Thu, 06 Aug 2026 22:13:11 +0000The third area to consider is the electronics, wiring and the control switches. SWB 911's have a variance in the factory blower controls - with many having no fan switch, so you will need to install new switches and connect them to our A/C system. Our 'Gen2 Blower's are supplied to plug straight into the original factory F and G body loom to use the factory slide controller on the dash which comes with a three speed fan configuration. For the SWB installation you will have to replicate this using the plug and the pins are available, as per the example pictured below: 4 pin connector housing for fuel level sender. Porsche 911 / 928 - 90161289101/2 | Design911 The part number for the Pins is 999 652 351 22 (These are on back order in the UK however appear to be individually available elsewhere) The wiring details are key. These are fans are ground switching. Please take care to follow the original F / G body Wiring pin out. NB We use our own colour designations, Black, Orange Red Yellow. Black 12v, (Fused) Orange 0v (Fast) Red 0v (Medium) Yellow 0v (Slow) This can be wired up any number of ways, including any of these: 3 speed, rotary, toggle switch, push buttons. We suggest this is all done using automotive gauge wiring rated for 25A and fused at 15A. Mounting and positioning of the switch is down to the installer as there's a number of locations this could be fitted it is down to personal preference.Wed, 05 Aug 2026 12:43:02 +0000The second step for SWB vehicles is to address the ducting. SWBs have notably fewer paths for air to enter the cabin (than later cars). This is a challenge if you prefer to not cut the body metalwork. HOWEVER there are some clever workarounds. The first and simplest option is to feed into the original heating system ducting. Simply connect an outlet of the blower to this. You may need to plug openings and gaps where the original scoop interfaced. Another option is to use our Round Vent for 911 Clock Position Some years featured a clock, others did not. We appreciate that this is a compromise (to lose your clock) but our recommendation is to be cool and check your watch! The picture below shows a car with blanking panel in the clock position. This picture, below, uses dual clock vents which works well in extreme climates. You do also have the option of forming new openings in the car body to add under dash vents. We do not warrant this and this is entirely at the risk of the owner. Pictured below is an install that used our Round Vent for 911 Clock Position placed in new openings (cut into the body), to act both as footwell vents and to allow for recirculation into the blower to aid system performance.Wed, 05 Aug 2026 12:33:01 +0000The first component to address is the blower / evaporator unit. Our 'Gen2 Blower' is a direct fit for F and G Body cars. It is not a direct fit for SWB variants. The factory fibreglass 'scoop' / air inlet needs to be remodelled to integrate with our blower unit. We recommend removing the black plastic air scoop that comes attached to our blower, and then offering the blower unit up into position before making any modifications. NB The image above shows the blower end caps and frame, as a 'skeleton' for visual clarity. Once the angle of the blower unit is established you can make modifications to the factory fibreglass scoop. Please measure carefully before you cut any materials. We recommend the addition of a new lower support for the blower. See picture below: Once the scoop is attached it should look something like the picture below: The picture below show the fibreglass scoop attached the blower and installed into the vehicle.Wed, 05 Aug 2026 12:03:55 +0000Our A/C system is designed for installation into Porsche 911 models years - 73 through 89 however it is possible to fit them into the earlier SWB models from model years '65 to '69. Modification will be required to both the car and to the supplied kit to enable it work effectively in 911 SWB vehicles from this period. To be clear the current A/C system is not 'plug and play', and will require some modifications to make it work and fit effectively. We are working on a SWB specific A/C system but at present there is no date or price confirmed. Please see the steps required below to make this system work in a 911 SWB.Wed, 05 Aug 2026 11:54:54 +0000The 993 alternator should be fitted as per standard Porsche service manual. Key notes to be taken however are: The larger spacer (red arrow) is the first spacer to be fitted, because our alternator has an inset bearing, this brings the mounting face level with the OEM Alternator. The spacers arrowed green can then be used to match the height of the original spacer from the original alternator pulley assembly. The combination of 3 spacers should cover all models, e.g. single pulley (RS) / double pulley. Use as appropriate. Other than this please follow the Porsche Service manual for all fitting and technical information Regarding the rear 'cone', this should be fitted as it is also a load spreading device for the alternator nuts.Tue, 28 Jul 2026 15:36:01 +0000I guess this is subjective to some degree. Personally, I have never experienced this because the engine is usually producing more NVH than the compressor! Have a great trip!Fri, 03 Jul 2026 21:42:03 +0000This isn't an AC settings issue, it is definitely alternator / charging system. These alternators produce 75/80 amps at idle. Either the 'exciter' isn't working ( which is in the clock instrument) or there is wiring issue or perhaps a voltage regulator issue.Fri, 03 Jul 2026 21:39:33 +0000at 2500-3000RPM it produces around 60A max when measured at the alternatorThu, 18 Jun 2026 03:53:05 +0000Coming back to this we never got the charging issues resolved. Even with the 240A alternator and serpentine belt it still only produces 20A at idle of 800rpm. At idle the AC system drains the battery dropping battery voltage to as low as 11.8v. I've tried all sorts of settings in the AC system but when the compressor is on it just drains more than the alternator is capable of producing. I see everyone saying this alternator can produce 100a at idle but I'm just not seeing how.Thu, 18 Jun 2026 03:49:22 +0000Any update as to when the new heat pump and control system for the 911 might be available???Sun, 07 Jun 2026 22:01:43 +0000Jonny, hi! Yes, the original foam dampers were used at first, they were mounted according to the instructions. With the new mod the vibrations disappeared almost entirely and I no longer notice them inside the cabin. I'm quite pleased with the result, after about 100km of testing. Next month we're going on a 5000 km trip around the South of Europe and the AC will likely be used a lot. If there are still issues I'll write here. The 911 has the old F-body, from 1970. Perhaps the chassis that we have has a slightly diff resonant frequency or there is some other contributing factor that couldn't be anticipated in the original mounting design.Wed, 29 Apr 2026 15:35:37 +0000Did you use the foam rubber strips under the top bracket supplied?Fri, 24 Apr 2026 08:05:44 +0000Used four rubber dampers for an improvised compressor suspension. Tests next week 🙂 ISat, 21 Mar 2026 21:51:59 +0000Hello, When the compressor is on a vibration is heard / felt. What advice do you have to remove or dampen these vibrations? We're thinking of inserting rubber between the mounting bracket and the chassis. Good idea?Mon, 09 Mar 2026 11:31:07 +0000