I had posted last year about my taurus air conditioner having issues, and I finally just got around to getting a proper set of gauges.
Symptoms:
A/C doesnt work on hot days, only cold days. I can hear the compressor kick in on the cooler days, but never on the hotter days. A can of refrigerant was added last year thinking that the system was low. At that time a "low side' gauge was used, because it was all I had.
All last summer, if I left the A/C on high all the time, it would work. If I shut the fan off for even a minute, it would stop working.
This year, the A/C will only kick in on really cold days. I now have high/low gauges. The high side sits at about 75, and the low side is at between 70 and 85. If the compressor kicks in, the low side will drop to about 40.
Magnets work better when they're cold. The compressor clutch has a big electromagnet to pull in the outer plate. When the facings get worn, the magnet isn't strong enough to overcome the widened gap. Adjusted by changing shims between the clutch parts.
Mom's did that too. Fixing the clutch fixed the problem. Did you check for power at the clutch plug when the system is turned on?
snipped-for-privacy@hotmail.com wrote in news:1180749897.612352.33800 @q66g2000hsg.googlegroups.com:
all A/C pressures are load sensitive. load being the combination of temp, humidity, fan speed and condensor temp.....their are no FIXED numbers you can use as a bible....that said, with comp. running, clean condensor, condensor fan running, medium blower speed, windows up my numbers would be 38lbs/low side....200lbs/high side with an outlet temp about 40 degrees..........if comp. clutch wont close slap it with a broom stick to see if it will engage. if so you have clutch prob.....................kjun
The high side pressure should be more like 150 to 250 pounds. Low side should really be a little lower they you are getting, ideally it will pull it down to about 25 and then the low pressure switch will turn off the clutch till the pressure goes back up to 30+. Make sure you have the valves on your gauges closed when reading pressures, I left mine open once and it messed up the readings. It may be that you just have a bad low pressure switch that is sticking and not letting the system turn back on. The other posters suggestion of clutch clearance too large is something to check too.
I realized I made a little mistake when reading the pressures. The clutch wasn't engaged when I did the readings, so it was showing really high (roughly the outside temperature, which I have read is normal). When the clutch finally engaged, I had about 25 on the low side, and 75 on the high side. I let it run for a while before doing the "official" reading. From everything I have seen, this tells me that I was low on coolant, since the high and low side were both lower than they should be.
On saturday afternoon, I added another can of refridgerant. It took a while for it all to go in, and slowly the high side raised up to about
150 pounds. It was at that point that the can ran out of R-134a. I have since bought another can, but I have not yet put it in. The symptoms are now the same as they were last year. The compressor will kick in and run well for a while, then eventually it stops kicking in. If I leave the fan on high blowing frigid air, it will go as long as I want it to. As soon as I shut it off, I get slowly warming air. I'm going to have to put a meter on it to see if the clutch engaging wires have voltage to tell me if the clutch is trying to kick in. Since checking the clutch clearance is a bigger job, is there anything else I should look at? I'm not looking forward to pulling the compressor off to get a look at the clutch. Is there any other way to get at it, as it seems the frame of the car would get in the way?
Since when I was adding the refrigerant, the high and low side was still low, is it possible I'm still low on refrigerant? I have added about 2-12oz cans so far. Also, could this be a symptom of a leak?
According to the sticker under the hood my 2003 Taurus takes .9kg of refrigerant. 24oz = .68kg so you could still be way too low if your system was almost empty to begin with.
I'd try another can and see if that fixes it. If it doesn't then I would do as you suggest and see if there if voltage going to the compressor but the clutch not kicking in. If the compressor clutch seems ok then consider the possibility that the low side switch is sticking.
I am working on a 97 Sable with a good A'c system which is charged and which can have the ac clutch jumped with battery voltage. There is a module mounted on the battery guard between the battery and the driver's quarter panel which is a two stage module mounted to a module via a 1/8 inch foam gasket If I bump the outer part of the module(closer to firewall) toward the front of the vehicle and the other part of the module whilethe AC system is on, the ac clutch will engage and the system will start blowing ice cold. Anybody know what this module is called? Is it magentetically actuated and can it be disassembled?
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.