BTW, you can get R12 can taps at Autozone. I got a can tap one time when I was in Mississippi seeing family, and just last week saw the exact same one at the Autozone here in Pensacola. It's with the AC supplies.

Dale

 

http://yarchive.net/ac/hydrocarbon_recipes.html

 

OK - I found some camp stove fuel (80% iso-butane/20 % propane) - so I'm going to vac down the system again, add the 8 oz can of 80/20 - then top off with propane - should give me about the 50/50 mix I need.

Thanks for the link, JM1FD. I hope my BBQ pit Propane is not too wet. Since my camp fuel was only $7 - I don't have too much to lose - except my garage... Good thing I don't smoke, eh?

Looks like 100% propane is a replacement for R-22, not R-12 - now I is smarter !

I REALLY hope this works.

Jim

 

If you have a brand new drier in the system then you'll probably be able to get away with it. I wonder if there's a drier out there that you could put between the tank and the manifold to dry it out as you charge it into the system.

 

Well - IT WORKS.

Nice Ice cold air, even at idle. Vacuumed it down to 29.5 again, then charged with the 80/20 Camp stove fuel - the low pressure and charging line got ICE COLD and I knew it was GOOD. Topped off with propane until the sight glass was almost bubble free - I don't want to overcharge it and I can always add more propane later. Since the stove fuel can was about 6 oz of iso-butane and 2 oz of propane, and then I topped off with 4 oz? more of propane - I should be about 50/50 mix - I think I want 60% propane/40% iso butane - but its good enough for now.

900 RPM: low side 55, high side 180
2000 RPM low side 40, high side 215

cold at idle, and really cold at 2000. A few bubbles at 900, none at 2000.

JM1FD and Speed of light - you saved me from a new compressor, expansion valve and dryer - I guess the kind of refrigerant you use can make a BIG DIFFERENCE.

Pics of Redneck AC equipment are attached - KIDS, DON'T TRY THIS AT HOME. I am not liable if you win a Darwin Award. Adaper to camp stove bottle was made with a small camp stove base, short piece of heater hose, hose barb fitting, and a cut-off section of my old R-12 charging hose. Best part is I didn't ruin my $40 camp stove - I can still return it to normal.

Thanks again Everyone. Now I just need to fix my secondary boost issue...

Jim

 

Glad you finally got it sorted out.

BTW, Rube Goldberg called....he wants his charging apparatus back.....

 

I dunno about car ac...I'm a hvac/refrigerant tech...you never want 134 to go above really 200-210...considering r12 is about 1k+ a can...the xfer from alkyl benzen to poe is well worth it....or if you have alkyl benzene you can quick buy a jug of 416a(direct replacement for r12). /shrug work it how you want it....average car I suppose would take about 1-2lbs of gas.....but if you dont want the xfer ask a refrigerant tech to fill ya up with 416(hot shot)...its not cheap....but cheaper than actual r12 atm(not this knock off ****). a 24lb jug of 416 is about 280 around the dc area.....and btw this whole freon debate is bullshit....it completely depends on the system...

 

Charged 2 cans of ES12 into MANA system. Night and day! Blows very cool. On test drive (85degree) I had to turn AC to 2 and then 1. It was out of garage (not hot like staying in a sun), but I'm very optimistic. Will see what happens tomorrow.

I noticed, however, that after drive when come to stop - AC turns off, I judge by RPMs. Then it turns on few seconds later (5-10 seconds) and stays ON

 

Yep. Today I drove to work and noticed that AC cycles on stop lights

Judging by air - looks like it might be freezing

 

I was giving this thread some thought the other day remembering Speed of Light's earlier post about propane and others who mentioned that the R-xxx's were variations of propane.
My father's truck r-12 sys was weak this spring, 2 years after service, cools, but seemingly low on refrigerant. So I thought, what about topping off systems with propane?
Was pleased to see ongoing contributions to this thread. Thanks.

 

It seems like it's cycling when idle at stops and it takes a little time to get going. I charged 2 cans of industrial stuff. Maybe 1 oz less (2 short bursts to bleed charge line)

Should I order more stuff then?

What confuses me is why does it cycle on idle? Does pressure switch control low and high pressures?

 

Someone smart should answer this, but if you're getting air so cold that you're having to turn it down to 1 or 2 Fan speed, then the evaporator thermoswitch is probably doing its job and telling the ECU to turn off the AC relay so the evap doesn't freeze up. You can bypass all of this by running 12 + power to the black comp clutch wire. You can also bypass the pressure switch close to the dryer with a jumper wire. There's also a pressure switch built into the compressor but that shouldn't be cutting the power to the clutch unless you've got extremely high , high side pressures - like someone I know that filled their system with 100% propane... what kind of idiot would do that ???

 

I'd like to do more "detective" work. Seems like all switches located on a same circuit. I may go and add wire leads to sensors so I can hook up DMM and see what's going on while driving.

Today when car was on a sun - took some time (like driving out of neibourghood) to get it going. And it's cycling.

 

Katit - if I were you, I'd go buy the Harbor Freight AC gages that are on sale right now, pick up some R134a adapters for the fittings on the car - and dive in. You really can't tell what's happening otherwise.

If your AC is weak, then maybe you have a leak and need to add some more ES-12 or whatever you're using. Go download the PDF of the electrical/AC factory manual and start working through the system. It will be a learning experience - trust me.

Jim

 

Well. I charged it using HF manifolds. And I do have R134 adapters loong time
And I do have vacuum pump.

Currently I have enought learning expierence (I think) and need to figure out what happens in real life situation.

AC works wonder with open hood in garage. Pressures looked fine (30/250) at 2000 rpm also I was too lazy to re-program PFC and did it by feel. I went by trusing SOL and charging 2 cans.

Now I want to know for sure why exactly I have cycling compressor. btw, I know it's cycling only because of jumping RPM's (but it's not hunting)

FD's AC button doesn't really blink when compressor goes on and off. As long as it's "ON" light will stay on

 

The pressure switch by the receiver/dryer does cut the compressor out for both low and high pressure. However if you have a pressure low enough to trip the switch in that line, then your system is nearly empty. I would suspect either not enough airflow through the condenser causing the switch to trip out on high pressure, or the ECU intervening and cutting the compressor out because the water temperature is too high or the idle speed is too low and it is trying to prevent a stall.

 

That sounds like it can be the reason.

I have PFC. At what RPM ECU tries to cut it off? I noticed that car sometimes almost stall when I come to the stop. Then RPM's stabilize. Usually it happens when engine not warmed up

 

I'm not sure what engine speed it would be at...somewhere around 600-700 RPM??

I think (you might want to verify this in the PFC section) that you can go into the commander and see what it is doing with the A/C relay output in real time....on the other hand, the display may be for the A/C INPUT line.

 

Dale - you are right, again. I found an R-12 can tap/hose at Autozone for $10. So I guess I can kill the ozone with my last remaining can of R12 - of course now I don't need it since I've discovered Camp Stove fuel - so any of you guys want to BUY IT???

Very reasonable price - ha, ha, evil laughter..


Getting back to the Cycling compressor - I assume the PFC would tell you the ECM status of the AC relay - either on or off. But I know the pressure switch on the compressor can also interupt the 12+ to the clutch. If if were me - I'd bypass the high/low pressure switch (by the dryer) with a jumper - then tap into the clutch power wire with your DVM (downstream of the comp. pressure switch - right next to the clutch. Then drive around and see if something is cutting pwr to the clutch if comp pressure switch and the high/low pressure switch isn't doing it - it must be the ECU turning off the relay. You can jumper the relay and that should keep the comp on all the time. If the ECU is cutting power to the relay then I suspect either an ECU setting or the Evap Thermo switch - it would tell the ECU to turn off the AC relay.

 

FWIW, my understanding is that the A/C compressor is consistently "ON" only when the climate control fan is set to "2" or "4" when using the PFC.

:-) neil

 

Ok, now I understand little better. Does high/low pressure switch provide feedback to ECU? I think it does, there is lead on ECU.

If it's ECU - then it might be tought luck.. Other then fixing my obvious RPM dip - I will be out of ideas. PFC supposely cuts off AC when you accelerate. Based on RPM? Via TPS? All good questions..

Right now I may just tap into clutch power and observe when it happens to get pattern better. Maybe I will power LED from that line and put it on a dash with electric tape. Will be more scientific then

Now I just need to fix alternator that went out yesterday. This car testing me..

 

where is that came from?

I read tons of different topics/speculations on PFC and AC issue that goes about fan switch issues, etc.. There is no "for sure" info out there.

I think if I wire LED to the clutch - I will know for sure when it works. Probably it makes all sense in a world to replace that light in AC button with one wired to clutch switch.

Other then clutch - system is all mechanical. No other inputs.

 

Agreed, it's all conjecture.

However, all I know is that in hot & humid Jacksonville, FL, if I don't have the fan on "2" or "4" there is very little cold-air coming out of my vents, even at freeway speeds.

:-) neil

 

As I recall, it goes like this

A/C Button -> Freeze Switch -> Pressure Switch -> ECU -> Clutch Relay

They can all be thought of as simple switches in a series. (I realize the ECU isn't just a simple switch, but its inputs and outputs are either on or off). If they're all ON then the clutch should be engaged.

The pressure switch isn't really providing feedback to the ECU...it either "passes along" the request for A/C if pressures are good, or it will "prevent" the request for A/C from getting to the ECU if pressures are bad.

 

I think the PFC may cause control problems with the MANA A/C system but not the Denso system. I can tell your this: I installed a PFC (it had the internal wiring mods done by SR Racing - they snip 4 wires inside the box, can't remember why but the wiring mod is required by all US FD's and it shown on the one page instructions you get with a new PFC). But I did NOT make the external AC wiring changes that are also mentioned on the PFC install guide - you cut a purple? wire going into the PFC and splice it into another wire IIRC... My Denso AC worked fine - fan worked on all speeds - compressor came on - no problem. I've since taken the PFC out to troubleshoot other problems but I will be putting it back in, so I can tell you more later.

I need to look at the AC Clutch switch diagram again - as I remember, the power comes from Bat +, goes thru the AC relay (controlled by the ECU) and also in series with the pressure switch in the high pressure line by the dryer. So the clutch will turn off if either the relay opens or the high side pressure switch opens. Or the pressure switch on the compressor opens - Mazda doesn't even tell you that switch is there - but it is - mounted to the top of the Denso compressor.

The ECU gets inputs from the thermoswitch on the evap and the button on the dash (and alot of other sensors) - besides the thermoswitch telling it that the evap is about to freeze up, I think it will only turn off the AC for wide open throttle - I've have not read that it does it to save a stall at low RPM - but Dale Clark is probably the expert here...

Jim