The AC compressor clutch cycles on for about 2 seconds then off for about 3
seconds then repeats. It never blows cold. It worked fine a few days ago, so
this is a sudden onset of symptoms.

I have R134a. I also have a guage that plugs onto the Low Pressure Port. The
sad thing is that I've not used it for a few years and I forgot how.

I have to connect either the guage or the fitting that connects to the can
of stuff, but I can not connect both at the same time. I think I have to
take a pressure reading to make sure it is low. My guage has GRN, BLU, YEL,
and RED sections. Green is 0 to 25psi, blue is 25 to 45, yellow is 45 to 46,
and red is anything above 65, the guage limit is 200.

I need to re-understand the directions.

I _think_ I want the needle to be in the blue area or yellow area, but by no
means in the red or green areas. I have not checked yet, but I suspect it
currently is in the green area. Once I ensure that the pressure is indeed
low, then I can add a can of R134. One can should bring the pressure to
45ish psi.

I _think_ what is happening now is that my pressure is right on the line,
and when the compressor kicks in, the result is pressure drop below the
threshold of the Low Pressure Switch, so the compressor kicks out. This
causes the pressure to rise and satisfy the Low Pressure Switch, so the
compressor kicks on again. The problem repeats from there, and the
compressor clutch kicks on and off due to activity of the Low Pressure
Switch.

I've owned the vehicle for a year, and have done virtually nothing to it. It
has worked perfectly until today, when the AC elected to go offline. I have
no reason to suspect a leak at this time, but if the can of r134 does not do
the trick, then I'll need to take it somewhere for service.

All I can do to the AC system is put the stuff in, and I have to ask to be
sure I have the process right.

On May 8, 7:32 pm, "Jeff Strickland" <c... (AT) verizon (DOT) net> wrote:



Yep, needs a charge.. Does it have a sight glass? That would be better
than going by pressure. The average pressure with the engine idled
up to say 1500-2000 rpm will be around 35-40 or so.. I wouldn't go
above
the "blue" range. The head pressure will start cranking up. One way
to guestimate it is to just watch/feel the suction line, and the
drier.
When it's real low, there will be little sweatback on the canister.
If it's part low, that sweatback might not cover the whole canister.
If you charge it, and get a full sweatback on the canister, it's
probably
enough. The main thing is to not drop below freezing on your
evaporator
temp at higher rpms. That will cause "fogging" etc.. On a real set of
gauges, they have a evap temp scale on the gauges along with the PSI.
On yours, the green range is below freezing as far as the evap coil
temp.
If it has a sight glass, I'd use it. It will clear up when you get to
full charge.
MK

Jeff Strickland wrote:

www.aircondition.com specializes in auto A/C and has forums and FAQs.

I'm pretty sure that 45 PSI evaporator pressure is way too high and
will probably cause poor cooling and maybe even blow the high pressure
safety relief valve or even rupture a hose. The right pressure is
closer to half that when the outdoor temperature is about 85-95F.

I'd be hesitant about charging a system that quit working so quickly,
and I'd want a good garage or auto A/C shop first check it out. They
can tell a lot by just measuring the high and low pressures and
checking temperatures.

I don't have a guage set, so when my Ford's A/C gradually became weak
after 4-5 years I taped a couple of dial type thermometers to the
evaporator inlet and outlet pipes, wrapped them with insulation, and
ran the A/C blower full blast and the engine at 2,000 RPM while I
_slowly_ added refrigerant until both pipes were equally cold. I
tried this on a 1986 Corolla with a sight glass in the A/C, and the
sight glass became clear at about the same time the evaporator pipes
both measured 32F. Bubbles showed right away in the sight glass when
I turned off the A/C, indicating I hadn't overcharged the system. BTW
the much older Corolla needed a lot less refrigerant than the Ford
did, one reason I didn't buy another Ford.

<nm5k (AT) wt (DOT) net> wrote

Just using the sight glass can get you into trouble. Years ago I
refilled a Toyota by using the sight glass as my guide. I added
refrigerant until the bubbles were gone. I then drove the car around
the block and blew a hole in the condenser when I raced the engine. It
turned out that a desiccant bag in the receiver/dryer had ruptured and
mostly plugged the outlet tube from the receiver/dryer. The sight
glass was after the blockage. The lead to the formation of bubbles in
the refrigerant stream even though the system was properly charged.
Only by overcharging the system was I able to clear the bubble. This
overcharge lead to excessive liquid in the system and this resulted in
very high pressures when I raced the engine.

The correct way to fix the A/C is to 1) find and repair any
significant leaks, 2) evacuate the system completely, 3) refill the
system with the correct amount of refrigerant. You can use a good
gauge set to diagnosis the system to some extent, but you have to be
have a lot of experience. Even then, the gauges won't tell you how
much refrigerant is in the system. They will only tell you that at the
current conditions (outside temp/humidity, inside/temp humidity) that
there is enough refrigerant in the system to go through the correct
phase changes. They can't tell you that there is enough refrigerant in
the system for a different set of conditions.

Ed

"larry moe 'n curly" <larrymoencurly (AT) my-deja (DOT) com> wrote

Sounds like a poor reason to base buying decision on. I haven't needed
to add refrigerant to any Ford I've bought in the last 14 years. I did
have to add refrigerant to by 1992 F150, but only when it was 12 years
old. My 1997 Expedition was still on the original charge when I sold
it with 147,000 miles on the odometer (and it had front and rear A/C
units). I did have to add refrigerant to my 1986 Sable because the
original style "spring-lock" coupling leaked. However, I only had to
do it once and this was when I replaced all the original o-rings with
the better designed o-rings that Ford released. The original o-rings
would harden and start leaking after a couple of years. The better
o-rings lasted at least a decade (car was wrecked after that).

Ed

C. E. White wrote:

It's not just that, but Ford's attitude about defects never impressed
me. Both the dealer (was rated #7 in the nation for customer
satisfaction) and FoMoCo would tell me that every problem was
"normal", including the really bad bondo job just above the front
doors ("It's not a defect beause all the cars like that."), they
usually didn't have parts in stock ("Well that blower fan never goes
bad" -- when I picked up the car: "We had to go through three fans
before finding a good one"), but when they did have something it
tended to be more expensive than the comparable part from Toyota. And
for some reason, Ford plastic and rubber rotted a lot faster than
Toyota's.

My Ford has the better green o-rings but still leaks a little, and I
suspect Ford knew the couplings were still problematic because they
later redesigned them and added a third o-ring.

"larry moe 'n curly" <larrymoencurly (AT) my-deja (DOT) com> wrote

It sounds to me like your problem was the dealer, not Ford. And as for
part prices, in general I believe Toyota parts are far more expensive.
Her are some comparisons (taken from on-line OEM dealer websites):

Alternator for a 2003 Taurus - $255.12 MSRP / $180.32 Discount
Alternator for 2003 V6 Camry - $575.07 MSRP / $460.06 Discount
Starter for a 2003 Taurus - $184.78 MSRP / $130.60 Discount
Starter for 2003 Camry - $249.01 MSRP / 199.21 Discount
Knock Sensor for a 2003 Taurus - $28.93 MSRP / $15.34 Discount
Knock Sensor for a 2003 Camry - $165.10 MSRP / $132.08 Discount

A bad bondo job? Was your car wrecked before you bought it? For that
matter, why did you buy it with a bad bondo job? Recent JD Power
surveys have ranked Customer satisfaction with Toyota dealers near the
bottom. I have mostly been happy with the local Ford dealer, but one
of my co-workers hates the dealer I am happy with and claims they have
a horrible service department. But then I have rarely had to use the
service department and the last time I did, they were prompt and
efficient.

I guess different folks have different experiences. The last Toyota I
owned was a POS. The interior plastic warped and turned white in
numerous places, the paint literally melted away and the damn
alternator failed every year in August. Replacement parts were either
not available or priced like they were made out of solid gold. The
damn alternator was over $400 and they didn't sell internal parts
(fortunately I eventually found a source for the internal regulator -
the part that always failed). The stupid starter quit working, and
Toyota's solution was a new $500 starter. The damn thing just needed a
$0.10 copper bolt. It was a funny story on that. I took the starter
apart and determined that the copper bolt that served as a contact in
the solenoid was bad. I went to the Toyota dealer to buy one and they
just looked at me like I was from Mars. Their solution was a new
starter. So, I went to a local rebuilder. I showed the remains of the
bolt to the guy that ran the place and said something like, "I bet you
don't know what this is." He not only knew what it was, by brand and
model, but he gave me one he pulled out of a box on a shelf for free.
I made a comment like, "I guess you must see a lot of starters that
need this bolt." His comment was something like - "Those #$%#%
starters hardly ever last long enough for that to fail." So much for
Toyota quality. I can't blame the car entirely. It was driven mainly
by my ex-wife and she was hard on cars. Lots of short trips on city
streets. August in NC can be really hot. Toyota had mounted the
alternator right next to the exhaust manifold. I am sure on a hot
August day, with the A/C on full, and the car crawling along at 25
mph, the alternator must have been really hot, leading to the failure
of the internal regulator. I can't blame the ex for the crappy paint
and plastic, the plugged up receiver/drier, or the transmission
failure. Those are all Toyota's fault. Oh what a feeling, moving
forward, this changes everything, etc..... On a positive note, my SO
has a 2007 RAV4 and so far (6 months) it has been perfect. She is very
happy (except she wishes she had bought a Prius now). I have driven
the car extensively and my only complaints would be excessive wind
noise at Interstate speeds, mediore seats (base model), and poor
control design (It has the most bizzare collection of operating
controls I have ever seen). The engine and transmission are first
rate and it is one iof the easiest cars I worked on as far as changing
oil is concerned (4 cylinder sutomatic).

I think after about three years they realized the spring lock
couplings were a bad idea in some application. My 1992 F150 only had a
couple and they were in areas not prone to vibration. My newer Fords
didn't have them at all (at least on the A/C). For me the green
O-rings were the permanent fix. However, I replaced every O-ring in
the system and cleaned up all the sealing surfaces. Once the original
rubber O-rings leaked, there was a tendency for corrosion to form in
the female portion of the couplings. If you didn't clean them up, even
the green O-rings would leak. Definitely not one of Ford's better
ideas. Seems like the manufacturing engineers got the upper hand over
the design engineers on that one. At least the Ford A/C compressors
seem to last. I've never had one of those fail while I owned a Ford.

Ed

"Jeff Strickland" <crwlr (AT) verizon (DOT) net> wrote

If it went from working fine to not cooling that quick you probably sprung a leak.
But here is some general info that might help. http://www.vintageair.com/DownloadsS...ng%20Guide.pdf

There is a general charging guide there to but if your system went flat its also wet
and needs serviced.

GL
Dan