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Post by enigmas on Apr 23, 2023 4:39:40 GMT
Vacuum Switch Instruction SheetThis is the final post (well almost...apart from the condensor fan) for this blog on recommissioning an older style aftermarket under dash (former R12 refridgerant) Aircon. Below is the tech literature for "setting" the Vacuum Switch if used for locking up the overdrive clutch on an automatic transmission. Refer to the method and diagram in the previous post if using it in conjunction with an aircon system in a car. As a final note, I'm pleased to say that the recommissioning process and the various components that I added to the AC system in my coupe have all worked out. As an aside I've also learned a lot about car aircon systems. 😎👍
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Post by MK IA Norway Viking on Apr 24, 2023 10:12:26 GMT
Mounting and Connecting the Vacuum Switch.There were 2 options for this: * Mount it inside the car near the instrument pod fitted with the vacuum gauge. * Mount it in the engine bay in a suitable and accessible space. I decided on option 2, as both the A/C relay and a suitable vacuum source was close by. It would also simplify any vacuum adjustments to the switch, if needed. A few pix below show the small mount that was fabricated for the switch and where it was positioned in the engine bay. The vacuum switch is mounted to the left of the A/C Receiver/Drier. The A/C relay can be seen just below the coolant header tank. Below are the small vacuum lines that provide a vacuum signal to the A/C vacuum switch and the MAF sensor of the programmable electronic ignition system that the car uses. Thank you for sharing all this valuable information ! I think installation Aircon is something many club members will have an interest in, even though it means introducing a non-original aspect into Rover-motoring. A car that has been "converted"to running aircon will not be original any longer. Still - I have installed aircon in my 3-5 saloon - as the A/C mod is insignificant enough and because I am not driving a museum.
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Post by enigmas on Apr 24, 2023 11:34:28 GMT
I'm with you on the philosophy aspect of owning and driving P5 Saloons and Coupes Norway Viking. It can get very hot during the summer months in OZ, reaching from the high 20sC to 40C on occasion. So travelling in car with a cooler interior is a plus for me and my good lady. It's also possible to use the cars throughout the year in OZ, so why not.
I'm sure there are enough factory original cars remaining to one day display a few static examples in a museum but I'll leave that to the generations that follow who will only be able to ponder, the who, the what and the why of these cars from behind a barrier. In the mean time I'm going to enjoy using mine, modified as it is.
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Post by enigmas on Apr 27, 2023 0:50:24 GMT
Addendum Updates Tech Reports Videos & MiscellaneaFrom time to time this section will be updated with with varied tech information and personal feedback from my own experiences with the recommissioned (underdash aftermarket) Aircon system in my MK3 Coupe. Hychill Minus30 Refrigerant Manual.This will download as a PDF. It has a very useful troubleshooting section. hychill.com.au/media/pages/info/ff612b0629-1578467756/HyChill-Minus30-manual.pdf Update (27/04/2023)As of the time of writing I've yet to fit a "supplementary" electric cooling fan in front of the condensor. These original R12 refrigerant systems generally relied on a large mechanical fan that serviced both the car's radiator and the condensor of the A/C. Cooling a car's AC condensor is more of an issue when idling in dense traffic, due to low airflow, hence the fitting of electric cooling fans. * The condensor on my P5's AC system is an older style "serpentine" flow version. * Virtually (AFAIK) most modern cars are fitted with very fine tubed alloy "parallel" flow condensors. Parallel flow condensors due to their extremely narrow flow tubes can easily "clog" and cause cooling and A/C issues if any type of sealant is introduced into the system during periodic servicing. A clogged fine core parallel flow condensor can not be effectively internally cleared of obstructive material. In these situations they are generally replaced with a new unit. ReceiverDrierThese are generally fitted to older style systems. They generally have a small sight glass between the inlet and outlet port. Observations. The flow of refrigerant can be observed through the sight glass during operation of the AC. The Receiver/Drier has several functions. * It acts as a filter for any small amounts of detritus in the system. * It has an internal dessicant that absorbs any moisture in the system. * It acts as a reservoir for excess refrigerant. Note: Too much entrained air in the system will overwhelm the dessicant. Air is introduced through system leaks and poor recharging methods. The system should always be vacuumed down before a full recharge or after a repair where the system has been opened to atmosphere. Sight Glass. During operation apparent bubbling and swirling of refrigerant (as seen in the sight glass) is not necessarily due to moisture or air entrained within the system. It may also be due to low refrigerant levels or an undercharged system. Source: Ford XY/ZD Workshop Manual. Section 16-10. Diagnosis & Testing. (R12 Receiver/Drier AC Systems) * A/C systems do lose refrigerant charge over time. Generally over years in a properly sealed and well maintained system. Air in an AC System.Too much entrained air/moisture within the system over a period of time will cause internal corrosion negatively affect major components. Both the Compressor and the Expansion Valve will be seriously affected. A failed compressor will spread debris throughout the AC system.
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Post by enigmas on Apr 29, 2023 11:19:30 GMT
Youtube AirCon Videos
During the writing up of this blog I did a lot of research, technical reading and viewed a multitude of youtube videos. All I can really say is do the technical research, try and understand how a refrigeration/AC system works and then sift through the information from whatever source with care. Youtube tends not to discriminate between real expertise and true dumbasses. Certainly don't jump in where angels would fear to tread before you have a good basic understanding of the technical aspects of a car aircon system.
I'm going to post several videos of a technician (Paul) who uses the tag ScannerDanner for his Youtube channel. He is a mechanic, AC technician and lecturer at a technical institute who also runs his own business. The videos I have chosen are on repairs to older vehicles with AC systems that would have been fitted to P5 Rovers in the day. As a plus his videos are very entertaining and largely unedited. Mistakes when they occur are visible for all to see.
In the third video shown Dan removes a "serpentine" style condensor from the Jeep he is working on. This is the type of condensor that would have originally been fitted to a Rover P5 in the day. It is also the same style condensor as fitted to my coupe.
Enjoy, I think you'll find them both interesting and entertaining.
Well folks...I've had to add Part 2 to the above video to provide the context of exactly what can go wrong whilst focusing on repairing an old AC and then something quite unrelated also goes wrong as well.
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Post by enigmas on Apr 30, 2023 10:52:03 GMT
AirCon ID plateAs one of the last things to do (apart from fitting an electric condensor fan) was to make an ID plate for AC system on the coupe. I quite like making these plates but it then often means that the surrounding areas will look shabby in comparison, and then require a freshening up. Here's a pic of the little brass AC ID plate.
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Post by enigmas on May 3, 2023 1:30:15 GMT
Fitting an AC Condensor FanThose of you who have a technical interest in the maintenance and care of their P5 or P5B would know these cars relied solely on a mechanical fan for engine cooling. Even so from my reading of issues with these cars over the years a common thread has always been hot running when stationary for lengthy periods in dense traffic situations. This seemingly applies even in the UK. I'm also aware that to alleviate the issue in traffic many cars have been fitted with auxilliary electric cooling fans. A sensible modification. Mechanically driven fans don't generally move much cooling air during stop start idling in traffic situations. Basically then, the gist of the above is that it really wouldn't make a lot of sense fitting another radiator in front of the engine's cooling system radiator. Heat transfer is then reduced. So fitting an aircon condensor directly in front an engine's radiator doesn't sound like the best option if there are other alternatives. Due to summer temperatures in OZ at times reaching 40C and often in the high 30Cs I fitted a 4 core alloy radiator to my coupe many years ago. It is cooled by a flex fan with a partial shroud and 2 small supplementary electric fans. The 2 fans only switch on when the temperature exceeds 85°C or 185°F . The engine runs at a consistent 180°F without the electric fans intervening for most of the year. Summer temperatures will bring the fans into operation when sitting stationary in heavy traffic situations. With all the above in consideration I decided to mount the AC condensor in a lower location to where they are usually mounted directly in front of the engine's radiator. The following pix show the system layout and the current alterations that I'm making to accomodate AC condensor cooling. This is my coupe with the grill and the number plate removed. Note the twin cooling fans. This is the same view but with the twin fans removed. The AC serpentine style condensor can be clearly seen.
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Post by enigmas on May 3, 2023 10:05:50 GMT
Fitting an AC Condensor Fan_ Part2The picture below shows the 3 cooling fans linked together in their mounting frame. The condensor fan is the smaller bottom unit. The twin engine cooling fans are thermostatically controlled and are not in circuit with the condensor fan which is directly tied to the AC compressor clutch relay. Whenever the temperature control module in the car reads above the (currently) set temperature of 24°C, the module via a relay will switch on both the compressor clutch and the condensor fan until the temperature is pulled back to 24°C. The aircon will then cycle on and off to maintain this temperature. Space is obviously tight and the next images illustrate this clearly. The condensor fan fits into the space shown below. At this stage of resolving a suitable mount it was simply suspended in place by a wire bound to the top grill rail. Sections of the plastic fan surround at the top were trimmed back to clear the grill bars. Below is some of the fabrication required for the top condensor fan mount. Trial fitting the grill back to the car. Checking for clearance. Note one of the grill bars has by chance slotted into the opening of one of the condensor fan mounts. These mounts will need to be trimmed back slightly. The image below shows the fabrication of the lower condensor fan mount. This will be painted black once all the clearances for the grill are established. Also, the area marked with a white line will need to be trimmed back to increase clearance between the fan shroud and the panel it sits behind. Wiring-up the Condensor FanAlthough it may not seem like a taxing task, running the electical wire and connections to and from the condensor fan to the AC relay can take considerable time. The picture below shows the finished lower condensor fan mount (yet to be painted) and the wiring with connectors in place. This image shows the condensor fan fuse positioned to the left of the ReceiverDryer. If you look carefully, a small pilot light can be seen positioned just above and to the left of the electrical connector with the red paint mark on its side. The pilot light turns on whenever the aircon relay is powered up. Tight clearance on the Condensor Fan...but it does clear! 😎 Almost everything back in place. Note the air scoop. It can just be seen under under the number plate. The Grill back in place. The front number plate has been raised about 3/4" so that the condensor air scoop (just below the plate) can function effectively. There is more than adequate clearance/air flow behind the number plate for the electric condensor fan to draw air. The mechanical engine fan also partially assists by drawing air through the condensor during stationary idling situations. This was tested with a large cloth held in front of the condensor. And that's the end of the story folks. The AirCon system has been recommissioned and is once again operational in my MK3 Coupe. 😎👍
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Post by David on May 3, 2023 11:13:10 GMT
Permission requested to serialise this in Take Five, in the hope we eventually get a warm, hot summer :-)
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Post by enigmas on May 3, 2023 13:37:13 GMT
Permission requested to serialise this in Take Five, in the hope we eventually get a warm, hot summer :-) Sure, go ahead David, you're most welcome. 😎👍
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Post by enigmas on May 6, 2023 4:43:32 GMT
Condensor & Receiver/Dryer Function.
I just recently came across this Youtube video. It's to the point, brief, informative and clearly outlines the functions of the AC Condensor and ReceiverDryer. As an aside, the presenter of this youtube channel is quite quirky and his videos generally include physical dissections and informed explanations of complex mechanical and electrical components.
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Post by enigmas on May 6, 2023 6:56:29 GMT
How to find a Clog in an AC System
This is another relevant video by a clever diagnostic technician who was called in to fix a problem with a car's AC system. The technician briefly explains that the AC compressor was initially replaced on the vehicle in question without any improvement to the issue. The original diagnosis was incorrect, the fault lay elsewhere. The costs would have been passed onto the customer with I'm certain, a fabricated excuse by the initial repairer.
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Post by p5bcoupe on May 9, 2023 14:05:00 GMT
With all the posts about air conditioning it has spurred me on to dig out the aircon system I bought a few years back that's been stashed in spares container for a "rainy day". It came from a P6B so all of the parts should be good for a P5.
Not too sure if I will get around to fitting it, not sure that our UK weather warrants it so may end up selling...so,if anyone is interested please feel free to get in touch.
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Post by enigmas on May 9, 2023 23:06:08 GMT
With all the posts about air conditioning it has spurred me on to dig out the aircon system I bought a few years back that's been stashed in spares container for a "rainy day". It came from a P6B so all of the parts should be good for a P5. Not too sure if I will get around to fitting it, not sure that our UK weather warrants it so may end up selling...so,if anyone is interested please feel free to get in touch. Now come on John, I know you enjoy challenging projects and it would literally be the icing on the cake with your pristine P5B. These were cars originally built to a high standard and an aircon system in good working order only adds to the car's desirable specifications. Truly as far as modern cars go, I can't think of any that don't come fitted with an integrated AC system. And of course there are those intercontinental trips to France and Spain to consider. All the tech is readily available today and so much can be adapted to improve the system's efficiency without impacting on the car's performance. 😎👍
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