Here is schema's for my 94 so we can reference it.

Bottom line is that I need to start with simple indicator light powered by clutch and look for pattern's while driving

Worst case scenario - ECU control may need to be bypassed (relying on switches only) and switch made for ECU or "straight" modes. Switch can be used during street races I guess

 

That would be just other guess I think. Looking at schema - there is no differences between MANA and Denso. Therefore - I don't see how it can be different.

 

The switch in the center of the compressor is actually an thermoswitch which is set to turn the compressor off if the temperature reaches 356 F. The only mention I've seen to this switch is in the Service Highlights Manual.

 

There's no difference in how they're wired, but the two systems have different parts for the freeze switches, probably with different tolerances for resistance.

 

Damn - I've got a bad memory. The comp clutch is powered only by the AC relay - that's the only thing that can turn it on or off. The pressure and thermoswitches are in series with ECU Pin 11 - so it looks like if they go open, the ECU loses power at Pin 11 - and tells the AC relay to open.

If you want to eliminate the AC relay - just pop it out and jumper the two pins - that way you've taken the ECU out of the picture - then the only thing that could be cycling the comp is bad power wiring to/from the relay to the comp clutch - or the pressure switch on the comp (not likely if you're running less than 300/350 psi on the high side)... or a bad comp clutch itself

Jim

 

I agree with that, I just tried to point out that I don't see connection between PFC being more "friendly" and type of system.

 

See my previous post. That is not a pressure switch on the compressor...it is a thermoswitch.

 

I charged mine today, in a 75 degree garage I'm running 35/150 per the freeze12 directions and getting about a 49 degree discharge, I'd like to have fiddled with it more but the condensor started to overheat from sitting still and shot my pressures WAY up

 

i'm about to recharge my a/c system with the industrial es12a. I converted a couple systems to 134a about 5 or 6 years back, but my knowledge on A/C systems is minimal. (the rx7 was not converted)

The car has been sitting for several years. The a/c system was working good at the time when the car was parked. The a/c sytem didnt get cold when i recently got the car running again(5 years sitting) but i think there was still some freon in the system. Reason being, i was installing a temp probe through the radiator and i think i pushed a little too hard and put a small hole in the condenser because i could hear a pulsing sound from that area for about a minute or so. it just sounded like whatever freon in it was slowing leaking out.

I pulled the condenser out and there was no pressure in the system at this time. I inspected the condenser but couldnt find any damage where the probe pushed. i tried using compressed air and stuck the area where i thought the leak was in water, but that proved to be a waste of time, no leak or bubbles.

Now i would like to know what i should do next? i'm thinking of putting the condenser back on and charge with a half a can of freon with dye and then see if i can find the leak, then get it brazed. But i don't know if this is a waste of time and money.

Also assuming i can fix the leak, under my circumstances what do i need to recharge the system? Will i need more oil? I see people buying pumps to pull a vacuum... is this necessary? And will the gauge/valve sets for my old r134a conversions work with the es12a cans?

 

I would put everything back together (under GP, I would also replace the receiver/dryer.) and I would rent or pay to have someone pull a deep-vacuum, for 15-30 minutes to see if there are any leaks and to remove any moisture.

If there are leaks, I would recharge with a refrigerant that is compatible with whatever was currently in there along with a U/V dye to find the leak.

:-) neil

 

You might try hooking it up to compressed air again and spraying it down with soapy water and looking for a pile of little bubbles to form.

If you have the stock parallel flow condenser, then it is FULL of TEENY TINY little passages. Repair isn't feasible.

Oil...probably wouldn't hurt to splash in .5 to 1 oz of oil. Pulling a vacuum WITH A PROPER ELECTRIC VACUUM PUMP is necessary. The pneumatic vacuum pumps don't draw a deep enough vacuum to boil the moisture out. It serves to remove the air and moisture from the system. Air does not a good refrigerant make.

You should also replace the receiver/drier since the system has been open to the atmosphere.

 

Are you sure the stock condenser can't be repaired? It looks like it has several horizontal passages. Even if one was blocked off entirely it looks like it has several more to flow past. Unless it snakes back and forth? As far as replacing the drier. It hasn't been open long and i have rubber caps sealing off the pipes. Does this make a difference? Or does moisture still find a way in? I have a friend that has a leak sniffer and it has something to pull a vacuum so i think i can go this route. What kind of oil should i get i think the system has always had r12 in it

 

Did the system have POSITIVE air pressure while sitting around ?

If so, and you capped the system, and you're not in a humid climate, you MIGHT get away with it, but IMHO, I wouldn't take the risk, esp. after 5-years.

R12 used mineral-based oil, so you need to use the same.

Also, since R12 is fairly expensive, you're better off recharging with the ES-12 with the U/V dye already added.

IMHO, the cost and probability of repairing a leaking condenser is not worth the gamble.

:-) neil

 

the system did have positive pressure while sitting, though i think much of it leaked out over the years cause it didnt cool at all. then the pressure was leaked out when i pressed the probe into it. i would say it was like that for 2 or 3 weeks and then i pulled the condenser and put plugs on the hard lines. I live in tx which is fairly humid though we haven't had much rain during that time. Can dryers be purchased at auto parts stores? Mine is a touring version so it has that particular a/c system with the dryer and clamp that straps on. Are the driers interchangeable?

Is there a good place to get a condenser if i fail at fixing mine? I was just going to braze it myself so it would be basically free.

And yes i was planning on using the es12, i wanted to use the industrial kind but i dont think it has a dye.. does anyone know? I suppose i could get a can of the stuff with dye and if it leaks out i can see where it is coming from. if it stays in there i can vent it out and recharge with the other stuff... what do ya'll think?

i also noticed that this place http://autorefrigerants.com/co00033.htm has a "proseal" stuff for sealing metal parts like the condenser. you think this would work? Whatever hole i created is small enough that compressed air doesnt come out, yet large enough that r12 leaked out pretty quickly. I think i read that the es 12 has slightly larger molecules so it might be more resistant to leaking out also...

 

Based upon the above, you should get a new receiver/dryer.

While all receiver-driers work just about the same, the connections usually are proprietary, thus you'll have to jerry-rig it to work.

Save yourself the time & aggravation by purchasing a new one from Ray Crowe @ Malloy Mazda, and he can provide you with the condenser as well.

You could try the ProSeal before all of this, but usually doesn't last long (I've tried on another car - lasted 2-months).

:-) neil

BTW: via parts.com, condenser will be about $480 and $141 for the drier, Ray is usually cheaper, OR purchase a used but in good condition condenser in the parts forum!

 

Yes, there are other passages the refrigerant can flow through, but you've reduced the already meager system capacity by killing one of the tubes, and how do you know you're not going to introduce a bunch of contaminants such as (from brazing) into the system? Would you rather buy a condenser now, or buy a condenser, compressor, and expansion valve later?

Moisture finds a way in, and the desiccant in the drier will snarf up any moisture it can get ahold of. As stated above, I wouldn't risk it. Again, would you rather buy a drier now, or a whole new system later?

Leak sniffer that has an integrated vacuum pump? Never heard of it. You should use a quality 2 stage vacuum pump with new, clean oil in it.

R-12 systems use mineral oil.

If you want a reliable A/C system, don't cut corners. Period.

 

No. The drier on this page appears to be the one for the Nippondenso system: http://www.ackits.com/merchant.mvc?S...Mazda93RX7_1-3

If your friend has a sniffer, put a can of R-134a in the system (DO NOT RUN IT WITH R-134a) and have him use the 'ol leak sniffer on it.

I suggest that you do not use a sealer. Lots of sealers work by hardening when they touch air. Guess what happens when you open the system up to do a repair after putting sealer in? That's right! The sealer that's all over the inside of the system hardens because the system is open and exposed to air. What does sealer hardened all over the inside of the system mean? ALL NEW SYSTEM.

 

i thought the driers were only like $10? wasnt there some information that the es12a formulas don't become corrosive even with moisture in the system? i'll be honest i would like a good working a/c system but i dont have $500 + to be spending on it. If driers and condensers are that much ill probably just take my chances running a vacuum to get what ever moisture i can out and repairing what i can then charging it with the es12a. is there a reason the moisture wont come out of the drier when pulling a hard vacuum?

Also what my friend has is an a/c vacuum pump with gauges, and a charge system. He also has a leak detector which is separate. Has dad used to have a small automotive shop that was left to him when he passed away, so he has all the equipment and a general knowledge on how to do it but isnt a professional.

 

From what I've read, newer desiccants have such an affinity for water that they don't release the moisture they've trapped until they're heated to upwards of 400 degrees.

See the link I posted above....they have what appear to be Nippondenso style driers for $7

 

The HC refrigerants don't react with water, but what about all the other materials in the system? They're not designed to operate in a wet system. Moreover, you can get ice particles clogging up your expansion valve if you have too much moisture in the system.

 

yeah i think i might get one of those $7 driers, there is no way im paying 100+ for something like that. Thanks for ya'lls help, now i have a better idea of what path to take. I'll probably order one of those driers, put everything back together, pull a vacuum on my friends equipment, see if it holds, if it does seal ill put 2 cans of the es 12a industrial and a small amount (half a can?) of oil. of it doesnt hold vacuum, ill put a can of r134 with dye in it, use my friends sniffer, find whatever leak is there and fix it if i can. Then ill be good to go with the es12a.

 

Yeah....half a can of oil or less (assuming a 2oz can). Can you still even get mineral oil in pressurized cans? I haven't seen any at the auto parts store in ages...all they have is the PAG and POE which isn't compatible with mineral oil.

You don't need the dye in the R-134a if you're using an electronic leak detector....pure R-134a should set it off no problem. Remember, don't run the compressor with R-134a in the system.

 

i have no idea if i can get mineral oil in pressurized cans. Maybe i will not worry about the oil, i don't think i have lost any. Will i lose any when i pull the vacuum?

I figured i would use the dye so i can pin point where it is coming from. For instance if its on the back side of the condenser the sniffer will let me know its on the condenser but i wont be able to see where it comes out, especially since i already tried to look for leaks on it. With the dye i should be able to see the exact source. That's my thoughts anyways.

 

What if the entire system sat open in a controlled climate (spare bedroom in my house) for 2 years?

 

On some systems I've vacuumed down I've found traces of oil and dye in my vacuum pump and in my pump oil. The majority of the oil should stay in the system. Like I said, if it were my system I would add 1/2 to 1 oz of oil just to be on the safe side.

Dye is really for more for finding small leaks and that takes a week or two for enough dye to come out to be easily spotted. If you have a medium/large leak you should be able to hear the R-134a hissing out.