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NVMyMPG
07-17-2012, 04:37 PM
OK. My A/C would not cycle at all. Hit the button and nothing happens. I followed the troubleshooting section in the manual and tested the low pressure switch. I pulled the plug and jumped the pins and when I hit the A/C button the compressor started, the engine increased RPM, and the fan came on all as it should. I went to the junk yard and got another low pressure switch and replaced it but the A/C still does nothing when I hit the button. I know that there was no freon in my system even before I messed with the switch. I plan to refit everything with a R-134 kit and reseal everything but I want to make sure the the mechanical portion of the system works before I do it. Would there being no pressure in the system make the switch not activate or did I likely get a bad switch from the JY and I just need to order a brand new one?

HLW
07-17-2012, 09:56 PM
The switch is there to protect the compressor form too much or too little pressure in the system. It disables the AC below 28PSI and above 374PSI if it is the tall binary switch or below 28PSI if it is the shore low cut-off switch. Either way it is working properly by not letting the compressor run when there is no refrigerant in the system.

lostforawhile
07-18-2012, 03:47 AM
what compressor do you have? f it's the Keihin, you'll have to find the stuff to do the conversion to the other compressor or stay with r-12, the Keihin does not like to be converted, and if it goes bad all the rebuilds are junk

NVMyMPG
07-18-2012, 08:12 AM
I believe I have the Denso compressor. Is there anything else I should do besides just replace all the seals and the fill plugs? I want to try to get this up and running as cheaply as possible. I think all of my parts are there and working but the seals are bad and it let all of the freon leak out.

Oldblueaccord
07-18-2012, 08:17 AM
I believe I have the Denso compressor. Is there anything else I should do besides just replace all the seals and the fill plugs? I want to try to get this up and running as cheaply as possible. I think all of my parts are there and working but the seals are bad and it let all of the freon leak out.


Cheapest way is try Freeze 12. No oil change. You will still have to fix any leaking seals first. Dunno if its available in your area.


wp

POS carb
07-18-2012, 10:03 AM
if you jump the wires and everything works properly then you have the wrong amount of refrigerant or a bad pressure switch. The only way to know if the switch is bad is to check the system pressure.
If system pressure is within the limits then you need a new switch.

Drier MUST be replaced if the system is opened for more than a few minutes or if condenser, compressor, or evaporator are replaced. Also very important to make sure you have it hooked up in the correct orientation.

Expansion valve SHOULD be replaced. It's a pain in the ass but if it isn't operating properly the a/c will never reach it's correct temperature/efficiency. If you are changing to 134 you will have to flush the system out and the valve needs to come out to do that so do it! They are cheap, like $10.

Flush everything. Our cars have early style serpentine condensers so it can be done. Fill with 120ml (4oz) of PAG
Vacuum the system for a few minutes. I modified a spare a/c hose and used the engine vacuum, way faster than those stupid 1/4hp electric pumps (they recommend at least 30min vacuum on those). Once you have vacuumed the system close the valves and let it sit for a few minutes with the engine off. Listen for hissing and watch for falling gauge readings, this is a sign of a leak. If no leaks, proceed to fill.

and 24oz of R134 or until sight glass is clear. Do not overfill. It may be a little colder at idle (like 5 degrees) if you do but at operating speed you will eventually damage the compressor. I get 40 degrees outlet temp with 2 cans of 134. Make sure at least 1 fan runs when a/c is on.

do not cheap out on a/c, it is more expensive in the long run, learn from my fail.

rc00netzero
07-19-2012, 07:52 PM
NVMYMPG - Most AC flushing products warn against using on the compressor. IF doing a full flush, remove compressor and on a workbench drain its oil and flush it with your new oil a few times. Turn it by hand to work the oil in and out. WATCH for any signs of trash or debis that would indicate it needs replacing. A good unit will be clean inside except for the oil which will usually be clear or green. Use rubber plugs to seal any and ALL open lines/connections when you are not working with them. Cleanliness is CRITICAL. Lube o-rings with AC oil or pure mineral oil. Definitely replace the drier - it's cheap and if the unit is original is OLD - BUT put the new drier in LAST - right before you seal up the system. Keep it factory sealed till then or it will suck moisture out of the air ( it contains a chemical moisture absorber/dessicant).

GOOD LUCK

lostforawhile
07-20-2012, 03:58 AM
NVMYMPG - Most AC flushing products warn against using on the compressor. IF doing a full flush, remove compressor and on a workbench drain its oil and flush it with your new oil a few times. Turn it by hand to work the oil in and out. WATCH for any signs of trash or debis that would indicate it needs replacing. A good unit will be clean inside except for the oil which will usually be clear or green. Use rubber plugs to seal any and ALL open lines/connections when you are not working with them. Cleanliness is CRITICAL. Lube o-rings with AC oil or pure mineral oil. Definitely replace the drier - it's cheap and if the unit is original is OLD - BUT put the new drier in LAST - right before you seal up the system. Keep it factory sealed till then or it will suck moisture out of the air ( it contains a chemical moisture absorber/dessicant).

GOOD LUCK
you don't want mineral oil if going 134 a thats the issue with flushing in the first place, you absolutely want to drain out and get as much mineral oil out of the compressor as possible, it mixes with the oil for the 134a and turns into some kind of nasty crap

DBMaster
07-20-2012, 05:59 AM
^^All the literature I have read says it does not do that. Sure, it's a good idea to get it out of the system
(if you are going to go with straight R134a), but you don't have to be fanatical about it. The mineral oil is not miscible in R134a so it will just settle into the low spots in the system and stay there. If you go with Freeze 12 instead of straight R134a you don't have to worry about it because the refrigerant that makes up 20% of the Freeze 12 blend will carry the mineral oil. My mechanic also likes Freeze 12 because, even though it is 80% R134a, the blend runs at pressures very similar to R12 pressures. That is what my system was filled with for the two years prior to getting rid of the car.

Dr_Snooz
07-20-2012, 05:30 PM
You're both right. PAG oil will react with any remaining mineral oil in the system and create a nasty corrosive mess. Ester oil will not. Double-end-capped (DEC) PAG oil will also not react.

DBMaster
07-21-2012, 07:19 AM
LOL! I like it when we can both be right! I guess now all I have to think about is the phasing out of R134a that is supposed to happen soon. At least there are already replacements for it that have been out for a while (supposedly to improve the performance of R134a systems).

My current A/C blows at 45. Not too impressive. The windshield is HUGE and the dashboard seems to have acreage on top of it - all black. I guess it is adequate. On a 100 degree day like yesterday I can stay reasonably comfortable with the fan speed on 2 or 3 (out of 4). Putting the fan on 4 creates so much noise! I am weird about temperature, though. I was never 100% happy with the Accord's A/C. I was used to MUCH colder and more powerful chilling in my 72 Pontiac. It had a compressor almost as big as the Accord's entire engine. (I'm exaggerating, but the old Frigidaire A6 compressors were very big.)

rc00netzero
07-21-2012, 07:28 PM
DBMaster - If you are getting 45 degree (F) air out of your AC on a 100 degree (F) day.. I am impressed - even if you are not. :D