mwpayne

I need a bit of assistance if you do as I'm attempting to install one I've had for a while in my 74 repu. I have about 90% of the parts, but not sure what all I need or where everything goes, so if anyone would be willing to send a few helpful emails and pictures my way, I'd be grateful.

Thanks.

ratboy

iTrader: (1)

I have AC in mine but the the blower just doesnt run. It hasnt really made my list of things to work on yet but everything is there and hooked up so what do you need pictures of?

mwpayne

Cool, (or not.., thanks. Really, some shots under the hood where all the hoses and lines run to and from the compressor and condensor. Also, if there's an expansion valve, where is it and how is it hooked up? That's one of the parts I'm missing.
Once I have that, I may bug you about which wires hook up where...although unless I can find a bracket for the compressor, it's all irrelevant at the moment.

I really appreciated it. You can post the pics here if you like, or email them to paynemw@charter.net

GORacing

Expansion valve is attached directly to the evap core, on the high side line, will have a capilary line going into the case. You have the factory York type compressor? I'll look in the morning for a mount...

mwpayne

York style? Hmmm, well, compressor says Denso on label, so not sure on that one. Hoses were cut off, that's why I need pics on where they go and lengths so I can get new ones. GORacing, If you have an extra bracket I'll gladly send you some happy bucks for it, and thanks for the help!
Also, no line going into the evaporator casing at all, I may have to open it up and see why......is it possible this old a unit never had one?

mwpayne

Wait..here it is, right? Hidden under a bunch of sticky insulating material. No line or electrical connection going to it, though. Should there be one?

GORacing

That is it... now the normal recommendation is that if the system has been open for any length of time, to replace the expansion valve as it has a vary small sliding valve in it and dust/dirt and corrosion will damage and cause it to fail in operation... next basic plumbing is from the high side of the compressor to the condensor (front of rad), Dryer then to the expansion valve, evap core then back to the low side of the comp so you will need to measure for lines accordingly.... A good automotive A/C supply parts house or repair shop will have all the correct hoses and connections to fabricate a new system... As far as Compressor brackets go, they are type dependant, early Yorks were found on RX-2, -3, -4, REPU ( not sure if these were on Cosmo's), and are the same bracket for 12A or 13B (sorry, the York type comressor looks like a Briggs&Straton Lawn mower engine with out the flywheel and cooling shroud and the newer compressors are alum and cylindrical and are generally simular to what you find in the RX-7), were as the newer style ones can be found on later -3, and early 1st gens... need to know which compressor type you have for the correct bracket set.

mwpayne

Alrighty, well this 'denso' compressor is very typical looking, very similar to the types I've had on my 1st gen RX7's and such, so I suppose I'm ok with one of those style brackets.
As far as replacing the expansion valve, I'll try to pick one up when I pick up a new dryer, hopefully it's as easy as that. Got new hoses for the condensor made up today. I'll need to figure out lengths for the ones that go out of the compressor, those were cut.
I'm betting, though, that the bracket may be the biggest challenge to this project...

mwpayne

Ok, thanks to helpful forum members, I have the compressor worked out. I still have a couple of wiring issues I'm not sure of, however. This is an 'add on' A/C unit, mounted under the dash of the truck. Mounted on the unit is a small control box with several wires coming out. The box has a relay inside to trigger the compressor on and off, no doubt.
I figured one wire had to be tied to 12v, one to ground, that left three others. Obviously, at least one would go to the clutch solenoid, I assume the other two a pressure switch ( the unit I have doesn't have one), or does anyone have any guesses where else they might go? At this point I've no idea what wire does what, and these old units are not plentiful enough to look at someone elses hookup easily.
I'm no A/C guy..how would the unit know when to turn the compressor on and off anyhow? Perhaps one wire should be tied to the unit that I haven't got hooked up? I appreciate any insight.

GORacing

Ok basic wiring for the old dealer installed a/c units... 2 switches, one temp control and the other fan speed, the fan is usually the "master" with main power in, then when turned on power is split with multiple wires going to the fan resistor pack located inside the duct work of the evap unit (id by three to four different size coils of wire hanging out in the air path, then one wire from the resistor pack out to the fan motor), and the temp adjust control... the temp control is a mechanical device with a capilary tube attached to it and running into the evap air duct, when air temp changes the gas in the cap tube and switch assembly changes pressure, the **** adjusts a variable spring on the switch, when pressure overcomes the spring, the switch changes causing the clutch (hopefully through a relay), to engage or dis-engage as evap outlet and cabin temp goes up and down... hopefully you will see enough there to make sense, or maybe some one else already has a schematic, if not PM with exact colors and I can draw up a schematic

mwpayne

Thanks, 'GO', that helps a bunch. I've got the fan motor already wired up, all the speeds work normally. I just wasn't sure that the rest of the unit would work when I finally got the compressor installed, ect.
Are you saying I could get you the wire colors and you could draw up a wiring diagram for me? If so, that's WAY above and beyond, but would be outstanding. I could post pics of the control box itself as well if it would help, as the wires are so faded you pretty much have to open it up to see the correct colors.

GORacing

Yes, post picture and I can compare to units i have and can draw up something... question - have you run across a small black box about 1"x2"x2" with 3 or four wire coming out of it and an adjustment screw in the side of it (if so this is a low RPM compressor cut out, used to cut the clutch off if engine rpm drops too low) ... or do you have an A/C idle compensator (vacuum pot with a J-hook on it that bumps up the idle with a solenoid and vacuum line going to it)? if none of the above we can include a idle kick up circuit that can be hidden under the aircleaner if you need...

mwpayne

No, I haven't got what you describe at all,unless this is the box you mean? It's mounted on the back side of the unit in the cab passenger side. No access hole to the adjustment pot you see there, I assume it's for setting the clutch on/off.
I hope to one day be in the position to have to worry about the idle (that would mean the a/c is working!).
The engine itself is strong, I'm hoping it won't be a huge issue, but it's good to know you've got a fix in mind. Here's the box's innards:

mwpayne

Hate to bother you, Goracing, does this in any way resemble your setup?

GORacing

oops sorry, no bother, that is not the low rpm cutout unit that I have seen... I was digging through all my spare a/c stuff and have not found it yet (and I cannot get to my -3 to take pic) post pics of other switch wireing so I can compare and get you a schematic if still needed...

mwpayne

Well, I think I've figured out ground and 12v, simple enough. That leaves three wires. They are all three quite long, as if going through the fire wall to do something. I assume at least one for the compressor clutch (only one wire hanging loose off the compressor I have), but I don't know what the other two wires are used for, unless for a pressure switch?
One didn't come with this kit, I wonder if the unit would run ok without? I just don't know enough about A/C to hazard a guess, but when this little adventure is over, I bet I'm 'schooled'. Fortunately, my neighbor has a vac pump, gauges, etc, and the know how to use it. When/if I get to that point.

Not sure what you mean by 'other switch wiring'? This is all I have...unless you mean for the fan assembly? I think I'm ok with that, you may mean the temp control, however. If you need that, I can pull that out if it would help figure out the rest.

GORacing

oh rats... you did post saying you had the fan part figured out, ok, will get back to you with a schematic for the remaining wires...

mwpayne

Cool, thanks! So, your unit(s) aren't like mine at all? I assumed mine was a typical dealer install kit.

kansei

iTrader: (3)

Mike let me know about this thread after I just started the same darn thread over on mazdarepu.com. GORacing- sounds like you can help me out too, as I am finally getting my system wrapped up after not messing with it too much two years after pulling it off the donor truck. I already learned something reading this thread- I had only seen the York style piston compressors on pre-'74 cars- RX-2s and 3s. I had never seen or heard of a York compressor on an RX-4 or REPU. After having four RX-5 style Cosmos, I can pretty much rule out them ever coming on those cars.

I have attached a few pics of my under dash unit- basically what I have seen on every other A/C equipped REPU except Andy's truck- his is slightly different. As you can see in the one picture- I have the adjustable engine speed sensing relay- but there is one wire that the label on the back did not say where it goes- it is a cream color (maybe it used to be white, not sure). Do you know where that one goes? Also, is there a "starting" position you would recommend I set the adjustable switch to?

In the picture of my unit dropped down, there are only three wires that could get hooked up somewhere- I have two of them visible- a grey wire- goes off the left side of the picture (this one is fairly long), a blue wire with a female spade connector (not really visible- it comes out of the two switches' harness), and the red wire visible coming out of the fan motor with a eyelet connector on it. Even though it is red, with how short it is, I am assuming it is a ground wire, yes? Can you confirm where these three wires are to go?


Thanks!
Neal.

mwpayne

So much for me thinking all these units were the same! Neal, Your setup looks way different than mine, mine says 'mazda' nowhere on it, therefore yours is automatically 'cooler' (perhaps not literally)
According to GoRacing', he has more than one setup he can look at for us, I'm hopeful he can find the time to jump in here and perhaps bail at least one of us out and get one of these units running...

GORacing

Hi guys,

Had to regroup a little, only RX3 a/c units in garage, others are in attic and at parent's, however I found an old (at least 20 years), hand written schematic I did, but have no wire colors, I'll be swinging by to pick-up stuff from parents monday night after work... Neal, nice pictures, alittle different than what I remember also... on the speed sense relay did you find the wire that goes to the (-) side of the trailing coil to sense rpm, again I have no wire colors yet... these dealer installed units are an interesting setup, I think the differences are regional and probably from different venders,

kansei

iTrader: (3)

GO- yeah, got the speed sensing wire hooked up. The backside of my relay had a listing of the wires coming out of it and where they were supposed to go- except the mystery cream colored (it may have started it's life out as a white wire, but it looks like a light beige now) wire. I was assuming the coil wire did double duty as both a speed sensor and power, perhaps I was wrong?

Then there's the grey wire and blue wire on the dash unit, along with that really short red wire with ring terminal that sticks out of the fan motor.

Hurry up and get over to your parent's place! I need A/C!

Neal.

JM1FD

iTrader: (1)

I realize this is a long dead thread, but it is perfectly on-topic for me since I just bought a REPU and one of the first items on the to-do list is to add A/C. So...thread has been resurrected from the dead.

Does anybody have pictures showing how the stock condenser is mounted? There's only so many places it can go, and I have an idea of where the brackets should bolt to the body, but it would be nice to get some visual confirmation.

Also, was the question of wiring ever resolved?

kansei

iTrader: (3)

Got the A/C all sorted on my old truck, and going to start in on a "new" one this Summer. I'm sure I can dig you up photos of my old truck's condenser mounting and I have the wiring drawn out, too. Very simple.

Email me directly and I'll reply with whatever pics I can dig up.

neal@kanseirotary.com or kanseirotary@charter.net

Neal.