Seeker > 620 KC

Diagrams compliments of carpartsmanual.com The AC diagrams are in various places. Be sure to open the different ones and look for other pages. Sub pictures often show model or year variations, or other related components like the electric fuel pump (F) below. It did not come stock on most 620's only the ones with AC, campers, or other unique situations. It appears there was an early and late variation in this diagram. One would have to check the parts listing on the website to confirm this. Please note this diagram indicates a standard 7 blade clutch-type fan. This fan is the standard heavy duty clutch fan that came on the 620 L20b motors. Not sure about others it may have been on. It is NOT the heavy duty AC fan that actually came in the AC kits. This fan will be depicted in the next post diagram. If you go to Carpartsmanual.com and look at the individual parts listings below this diagram, you will see there are different part numbers for the different fans. There will also be a different pic of the 8 blade fan in one of the other diagrams. This diagram also shows the in-dash ducting and the backside of evaporator cover that goes in the passenger leg area, but this diagram does not show the center vents. Unfortunately, you have to move between the different diagrams to find all the variations of the AC parts. The factory AC fan had 8 shorter blades with more pitch vs. the standard 7 blade clutch fan with longer blades. Through junkyard prowling I have learned the 8 blade fan was also used on later model vehicles like the 1980 200SX with the EFI Z20 engine, and have matched them to my 620 AC fan. More pitch = more pulled air vs. trying to achieve the same by using more torque on a longer flatter fan blade. (But for all you minimalists who like to have manual fans and hidden wiring looms... at engine start-up, or with a hot motor sitting in freeway traffic... these fans do create lot of wind noise.) SAFETY TIP: Do not install AC and attempt to use a 4 blade manual (no clutch) fan with or without a fan shroud... you will overheat and seize your engine in short order! You may be able to get by with a 7 blade clutch fan and a shroud, but be sure to check the longer fan clearance with your shroud.There seem to be a number of different fan shrouds available from different vehicles. SAFETY TIP: If you are brave enough to install a new or used AC system on a used Datsun 620 engine with an old or original head gasket... Don't risk the life of your motor! You must ensure all components of the cooling system are in Excellent condition: Clutch fan is new or has great resistance when spun by hand (It should not spin a full revolution, if so replace it!) Thermostat is opening at 180 degrees Radiator is clean and not restricted Rad cap seals and works Cooling system has been flushed and runs clear Cooling system holds pressure - no leaks or seepages Freeze plugs look solid and are not crusty rusted or leaking (Don't forget the one on the back of the block between the engine block and trans!) There is the correct percentage of anti-freeze/coolant in system Heater control valve is not leaking Hoses are not soft, bloated, and are in good shape Oil change is fresh and regularly changed Fan shroud is whole, complete, and not cracked. (I've seen half-shrouds on newbs cars! Duct tape it if cracked!) Last, but not least... Ensure your temp gauge is working and accurate! Keep a religious eye on that gauge whenever using the AC, especially at low speeds or pulling a grade! If you maintain these, along with your AC system maintenance it will give you years of problem free cool to cold AC service. Remember this is 40 year old R12 evaporator technology. They did not perform like modern day evaporators. If you ignore maintaining the cooling system, you will kill your 35-40 year old motor very quickly. Stay cool!

Datsun 620 engine bay orig AC diagram from the 79 Datsun/Nissan Factory Service manual NOTICE: This diagram depicts the real 8 blade AC fan for the large 5" bolt pattern clutch-water pump. It eliminates the mechanical fuel pump and replaces it with a block-off plate. An electric fuel pump is required back by the gas tank. It requires an extra drive pulley on the crank. It looks like the same pulley that is rubber mounted within a 720 harmonic balancer, but it would have to be cut, pressed out, or heated up with a torch to remove it to match up. Wouldn't be able to do that in a junk yard! There are two different cooling housings for different year ranges. You'd have to go to the website carpartsmanual.com to look at the parts listings to see what the different parts went to which year ranges. The front idler bracket/support compressor replaces the timing chain inspection cover. Front cooling hoses need some re-routing.

Datsun original In-dash evaporator AC unit and drive belt diagram sourced from a 1979 Datsun Factory Service Manual. Note: This diagram shows the entire evaporator, but not the plastic cover that hides the evaporator and prevents passengers from kicking it.

There’s a guy I know with a blue 620 in LA who wanted AC and does not have a shop to work in, but he was very creative utilizing what he had to work with, for this idea we’d discussed together. And, he kept the orig R12 Freon, which is easier to keep in the system vs R134. (More later on R12 ca R 134) He used the original Datsun York 3 bracket system. But he still used the orig Datsun front steel plate bracket that also replaces the timing chain inspection cover, and he needed the 3rd short top comp bracket as well. It is a very complicated and ugly installation for sure, and makes access to other engine systems very difficult, but “Hey!” he has working AC in a 620! And he beat me by miles getting it up and working. He bought a generic Sanden rotary steel-plate compressor mount plate. Cut off part of the top of orig Datsun 12 lb bracket so the Sanden mount would kinda mount flat. Then he redrilled the Sanden mount, in order to bolt it to the 12 lb cast iron bracket. He still needed ALL the orig brackets. Unfotunately, it only has two bolts holding the Sanden bracket to the 12 lb bracket. And there was something hap-hazard about the belt adjustment. Can’t remember if he couldn’t use the orig idler pulley, or if the compressor was only held in with 2 bolts and swung out, the belt tightness/adjustment was just hinky. He said it used the rotation of the compressor pump to keep the belt tight??? i haven’t thought it through if I’d trust using the 12 lb bracket by itself to bolt a Sanden universal mount bracket to. The extra ft bracket gives the orig 12lb brkt one more mount point, as it has all different size bolt diameters attaching it to the engine. When I was installing and servicing these units in the 70’s I remember many of these having broken off engine bolts that had to be drilled out a retapped, some had to have motors pulled out to repair. Mechanics servicing or installing AC would over tighten bolts snapping them off, use impact guns in a rush, or simply leave bolts loose. The vibration from the York pumps cycling on and off would break bolts over time on these little alum head engines. My orig idea was to fab a newer Sanden bracket to fit the pass side of the motor, but there is still the challenge of not blocking access to the #1 plug. But the bigger hurdle for me.... I just too old, don’t have the welding skills, and don”t know anyone I can afford to make a simpler bracket. It is surely an opportunity for someone who does ? ( More in future posts about other existing aftermarket AC comp mounts on Driver side, with and without smog pump,) Somewhere I have a few pics I snapped of the blue 620 installation for a reference, but I don’t recall if this installation resolved the non-access prob to the #1 spark plug or not, listed in Gery's post above. Unfortunately, in his haste, he also used the orig worn out clutch waterpump with a 7 blade fan, and the orig receiver-drier, and had not reinstalled his fan shroud. He drove it to Eagle Rock Swap Meet and had serious overheating issues and the AC system was just cool, not cold. I had a spare 8 blade orig fan (with shorter blades and more pitch) I sold him. He bought a new clutch water pump, installed it all with his fan shroud, and resolved the heating prob. But he needs to get a new receiver-drier to take any moisture out of the system to make it blow colder. But to do so he’ll have to capture all the R12 Freon out of the system, R&R the receiver drier, fav the system, and recharge it with Freon. Tip: Never re-use a condenser drier that has been exposed to the air for more than a day I give this guy major kudos for putting together a working 620 AC AND a fairly bolt-on AC system, while living in an apt without having a garage to work in. His system gets him around LA, and to events and shows, But in the condition I last saw it, I would have serious concerns driving it long distance, like to the Fontana BBQ, or to the Williams AZ event . But with his kind of Ratsun ingenuity And determination I certainly have faith he’ll continue to get the dependability factor “dialed-in” over time.

As for the York compressor and Charlie's statement of horsepower robbers... those compressors were big, noisy, and created a lot of vibration. And on a 620 that only produces about a 100 hp, they could bog the motor down under cruise some, but heavily at low speeds causing them to stall often because... many of the aftermarket AC makers like Frigidaire (Frigiking and ARA) did not make as sophisticated AC units as Nissan, so they didn't put actuators that raised the idling RPM, etc. They also caused a lot of vibration at idle and low speeds, especially if the aftermarket brackets weren't secured well, or were stripped out on install by non Datsun shops. And the front seals often overheated and caused Freon leaks, on top of the leak causing slide-on hose fittings. This made a lot of 620 York owners give up on the complicated "modern" (at the time) AC and remove the compressors and leave them off their vehicles forever, leaving the lines, mount brackets, and condensers in the engine compartments and the evaporators in the dash... with no working fresh air vents after that! York got a seriously bad reputation like Edsel, some deserving, some not. But if maintained Yorks did a good job and lasted a long time. And they were the only AC option available on 620's and a lot of American cars for a decade or more. I believe Colour Box reasonably wanted AC in a hurry for the summer and just restored Factor AC using a York in her little Stanley 210. I can't wait to catch up with her and check it out. It will be a real flash-back to my Econo Motors Datsun Dealership days of installing AC in Riverside CA. More on Sanden and Hitachi compressors and more modern ugrade installations in my next posts.

Woo Hoo! Can't wait to visit with you again George. Love hearing your stories about being a dealer owner, and being able to ask you questions about "back in the day." Is your son Kevin coming this year? Hugh

I'm responding from work, so I must post in chunks. Thanks for bearing with me. I just checked the online version of the 1977 620 Datsun/ Nissan Factory service Manual and it too has a section on AC. My understanding is the 620 Japanese Factory AC began sometime in 1976. But having to print service manuals in advance of the vehicle model production year, I don't know if they got the AC published Factory Service Manual (FSM) in the 1976 Datsun/Nissan version or not. Tried to locate a 1976 620 FSM online without success. If someone has this manual and could confirm if it has a AC section or not it would narrow down and give proof to my understanding. Posting a pic of the FSM cover and table of contents would be ideal documentation, if anyone has those skills I seem to have lost or not kept updated. Much appreciated.

By what I hear And understanding the “antique” insurance status is only available if you register the vehicle with CA DMV as a historical vehicle. This may also incur more yearly state fees and could also limits how much you can drive it per year to maintain historic vehicle status. I suggest confirming this before eliminating your smog pump to install a compressor (pump) in its place. AC was not installed by the Japanese Nissan factory in early 620’s. When exactly they started is not clear. Many state-side dealers were buying after-market US made AC units (under dash and in-dash units) and installing them at their dealers or by local shops near them like ARA shops. Then the dealer sold these to car buyers as “factory AC.” None of these units were made in Japan despite having silver lettering on the AC switch control plates saying “Datsun.” This can be confirmed by looking at the compressor mount plates, fan squirrel cages, or hose ends. The compressor mounts are welded plate steel, the squirrel cages are stamped “Made in Ohio,” and the hose ends are slide-on with hose clamps. , Find a Datsun/Nissan published 78 or 79 620 factory service manual (NOT a Haynes, Chilton, or Motor’s brand.) Both year manuals have very good AC sections with exploded views of the 3 combined brackets (difficult to find in So Cal) it takes to mount the heavy square vibrating original York compressor on the passenger side of the engine. The main bracket is cast iron and weighs 12 lbs! It must be bolted to two other smaller brackets in order to mount the York compressor. image by Bash Barker, on Flickr The York compressor was not mfg by Nissan but was the only compressor used by Nissan for orig 620 AC, and was included in the Datsun/AC kits assembled at the Japanese factory. Nissan was using Hitachi compressors in I have these and can share them but am just getting back the skills for posting pics, bear with me.I also have pics of various mounts. More in my next posts.

Sweet!

I'll write you a note for time off from work. Let Jesus be your co-pilot for the ride Ted <sarc.> I'll even let you borrow my shade canopy so you don't lobster up again. I believe ER is 3 x's a year, which would make it in November. Typically, it's the 3rd Sun of the month. But I would check with Jose on that to be sure.

Just an interesting observation of us all. We're ironically funny creatures aren't we? We don't hesitate to shell out really big bucks for a big screen TV. But we sure watch our budgets on our 40 year old projects for our creature comforts, eh? :)

If it's humid outside... don't try and utilize swamp cooler technology. It only makes it worse. Living on the coast where humidity is always high, the hardware stores don't even sell swamp coolers till you get 30+ miles inland. But in Riverside where I grew up it is a desert... swamp coolers are king!

You'll have to pass it on to some lucky but sweaty southlander!

Colour Box gets chilly in the summer time! Success at last! Hopefully he installed a new receiver drier? That could contribute to it not being as cold as it should be. Remind him your evaporator is nearly 40 year old technology compared to today's standards! It won't quite as nice as modern, but far better than the Ghetto breeze ;)

Yes...I experienced it all driving up from San Diego thru Grants Pass to Canby and back last year. That's how I typically categorize the PNW...never dries out. But I was hypnotized by Canby the first two times I came up...sunny and warm!

I realize I'm from So Cal, and don't know the difference between showers and rain (its all wet to me)... there was only enough dry room for single table that didn't get soaked under my easy-up. . In the space next to me was James, His lady, and Gene. It rained so much on and off they went out and bought a giant blue tarp to surround their easy-up. It was like a giant blue cocoon that swallowed a boom box.

The VIN # is also stamped on the inside of the right frame rail by the oil filter or frame rail. One you clean it and copy the number, you might have better luck requesting one from P.O. or from DMV?

That’s why Colour Box was utilizing her Nissan manuals vs. someone’s old feeble memory like mine, or some’s Memory who believes they’ve seen it all ;) DatsunFreak is correct in his assessment of aftermarket AC units vs, Nissan beginning in the early 80’s. Early 70’s Datsuns did not come with AC installed and was done at the Dealer by their techs, or subbed out to local AC shops, some being ARA shops. But some early Datsun AC units did use the York compressors too and do show up in some Nissan service manuals. Later model Datsun branded vehicles did come across the pond with AC installed at the mfgr plant. I get this vrbal history from Fontana Datsun Dealership George Goespel at the real SWDP BBQ in Fontana CA. Nissan chartered a entire plane and flew him and his wife and other dealership owners to the plant in Japan for a couple weeks of plant tours and japan trips. this is why I try to make that BBQ every year to hear his Datsun experiences and aDatton history! I also have a handful of the parts diagrams for different Datsun models from my ARA days. There are a number of clear indicators to distinguish aftermarket AC units from Nissan. Like the plate steel mounting brackets vs, Nissan’s cast iron brackets, and the 620 bracket weighs nearly 15 lbs!

You might want to look up the orig cast iron bracket in her AC thread before recommending this. The orig bracket is a knarly thing, not quite as bad as the Nissan 620 cast iron bracket.

This might work depending if she has a smog pump to contend with. Being an 80 Ca vehicle I would think it would have a smog pump.

Yes, I'm familiar with ARA, I worked for them for a period of time before going to work for a Datsun dealer as an AC tech. I hate do disagree with you DF, but a number of the big 3 manufacturers installed AC in vehicles using the York compressors. And I never said the compressor was made by Nissan. Colourbox has a factory cast iron bracket from Nissan for a 210 that bolts to a York compressor in her AC thread. How do you explain that? ARA never made cast iron brackets and neither did the other manufactures of aftermarket automotive AC units like Frigikar, Frigking, Mark IV. They all used flat stock steel plate.

A road trip with a York would not kill it or Stanley :thumbup: Just be sure your mech installs a fan shroud if you don't already have one, I just got my 1980 and 81 service bulletins and they both recommend the fan shroud. And for sure check the water pump and clutch fan, they are both relatively cheap if you haven't done them previously. If not, might want to do it while you're in it. Over heating is a car killer.

And... the York compressor would be a stock Nissan feature, all 210 period correct, not a later modification or upgrade... if you happen to like true originality.

The bigger 510 compressor would easily be overkill, and not be worth extra cost for an 80’ 210 if they charge more for it. Not sure if it uses the same mounting pattern? York compressors were installed on numerous user vehicles new, and commercial trucks starting in the late 60 by the car manufacturers including Datsun in early 70’s, as it was one of a just few comp mfgrs then. Yorks were very effective in small to med cars, but many early evaporators could not cool large passenger compartments like a 510 wagon, vans, big station wagons, etc. and you,d only feel cool air going by the driver and shotgun passenger. Folks in the back would never cool off. Many York’s were Poorly matched with evaporators that were not capable or dependable, but most were not dependable because of hose barb hose fittings with hose clamps, and then when leaking, then never serviced. Untrained techs repairing new ac units used bare hands, causing new seals to leak right away. York’s created a lot of vibration issues, especially on loose mounts on aluminum support mounting bolts causing broken bolts in early Datsuns. York’s earned a fast reputation for poor functionality, when it was really a comedy of errors that gave them the bad rep, like the Corvair. York’s were a standard for a couple decades, and I still see some working today. I repaired and serviced them in the early 70’s at a multi European car dealership. Parts were prolific, easy to source, and the units easy to Easy to access and service. But, when they developed a bearing or seal issue, they were usually tossed by owners due to a high compressor replacement price vs repair. This was due to lack of success by mechanics repairing Freon components. Thus a high repair bill, and most folks just didn’t repair it or simply disabled the entire AC unit. Z’s and my 80 SX were already using Hitachi compressors by late 70’s, Sanden had taken over the aftermarket ac industry by 80, and York’s technology was already dying fast in 75-76. DatsunFreak is quite right about the difficulty finding parts for the York today, but I still see Four Seasons and other remanfgrs selling refurbed Units on eBay. If someone wants ac in their part time Datsun, an orig York could last them the life of the vehicle if the owner only uses AC 3x’s a year in the 1,000 miles they might drive their prize Show baby per year. if the owner uses his Datto as a DD needing AC in So Cal heat or AZ every day, i’d Find a fabricator to make a new comp mount bracket and install a rotary Sanden compressor like DFreak says for better functionality and dependability.

Holy crap! I’m with Datsunfreak. I suggest you ditch the square compressor and have someone make you a bracket for a rotary compressor. The York’s were a big draw of power from the engine and a vibration monster. I have an aftermarket diagram of a better current solution I’ll email you tomorrow.