AC Problem
#1
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AC Problem
My AC is blowing warmer air on the passenger side. The driver side is fine. I seen plenty of threads of all sorts of solutions but no definite answers of what the fix was. I tried the easier one first and bought a can of freon. But as soon as I connected it the pressure was 65. The instructions say then this is another problem and not freon. So I didn't pump any extra freon in. Any ideas?
#2
Was that 65 psi with the engine AC compressor turning? If true, then it is
A. Overcharged
B. Compressor failing while turning
C. Compressor clutch not activated, which means the compressor is not really turning.
Make sure the compressor clutch is engaged, and the center part of the compressor is turning at the same speed as the engine. Suction pressure should be about 30, and no more than 35 psi at idle duriong normal operation. Mine stays between 28 to 30 on a warm day.
The faster the engine and compressor turns, the lower the reading will be until it cuts off at about 15 psi. Then the compressor clutch will deactivate and stop the compressor until the reading goes back up. It should not go that low unless it is either very cold outside or you have a low refrigerant charge. You should not have a cold cabin if the suction pressure is reading at 65 psi with the compressor running. 65 is usually the pressure with the compressor off.
Please check the condenser coil in the front of the car. Directly behind the grille on the drivers side, there is a filter drier Small metal tank) with a sight glass on the top. Clean the glass if you cannot see inside. You should see liquid flowing past that clear glass. If you don't see any liquid flowing by, spray the condenser coils with cold water while the fans are blowing. That should reduce the pressure on the gauge.
I forgot to mention that if your condenser coil should be clean, and not filled with bugs and trash. Clean it if it is dirty. Make sure the fans are turning. If not, then th epressure reading will be high.
Hope this helps
A. Overcharged
B. Compressor failing while turning
C. Compressor clutch not activated, which means the compressor is not really turning.
Make sure the compressor clutch is engaged, and the center part of the compressor is turning at the same speed as the engine. Suction pressure should be about 30, and no more than 35 psi at idle duriong normal operation. Mine stays between 28 to 30 on a warm day.
The faster the engine and compressor turns, the lower the reading will be until it cuts off at about 15 psi. Then the compressor clutch will deactivate and stop the compressor until the reading goes back up. It should not go that low unless it is either very cold outside or you have a low refrigerant charge. You should not have a cold cabin if the suction pressure is reading at 65 psi with the compressor running. 65 is usually the pressure with the compressor off.
Please check the condenser coil in the front of the car. Directly behind the grille on the drivers side, there is a filter drier Small metal tank) with a sight glass on the top. Clean the glass if you cannot see inside. You should see liquid flowing past that clear glass. If you don't see any liquid flowing by, spray the condenser coils with cold water while the fans are blowing. That should reduce the pressure on the gauge.
I forgot to mention that if your condenser coil should be clean, and not filled with bugs and trash. Clean it if it is dirty. Make sure the fans are turning. If not, then th epressure reading will be high.
Hope this helps
Last edited by gserep1; 11-14-08 at 04:37 PM.
#3
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I'm getting the 65 psi with the engine on and AC blasting. I'm kind confused why my pressure is so high since your pressure is a lot lower.
The condenser coil seems to be working fine. I can see the liquid flowing. Thanks for the suggestions.
The condenser coil seems to be working fine. I can see the liquid flowing. Thanks for the suggestions.
#4
Read this. I think it will help explain your readings:
A/C Pressure Gauge Determines how much refrigerant is in the
system. It also provides a convenient location to attach other
service equipment to the system. Part of a Manifold Gauge Set or
built into a Charging-Recovery Station. Two gauges are connected
to the system; one for the low-pressure side and the other for the
high-pressure side. The gauges and hoses follow a standard color
code. The low side is blue and the high side is red. Each gauge
shows the pressure in that part of the system.
When part of a Manifold Gauge Set, the valves (marked Low and
High), allow one or both inlets to connect to a central passage (thus the
term manifold"). A third hose fitting is reserved for charging or
evacuating the system.
The center hose of a manifold gauge set connects to a refrigerant tank
for charging or to a vacuum pump for evacuating the system. Charging
the system must only be performed on the low-pressure (suction")
side. This prevents dangerous pressure from developing in the
refrigerant supply tank.
A/C Pressure
Gauge Connection
Note: Pressure gauges
are built into the latest
recovery machines.
The static charge (system pressure with system OFF) is also of value
when troubleshooting. The rule of thumb" is a 1:1 ratio on the gauge
reading; approximately 1 psig for every 1° F of ambient temperature.
Thus, on an 80° F day, the system should have approximately 80 psig
static pressure.
For your safety, ensure each hose is connected to the correct service
port in the system. On older CFC-12 systems, the two fittings may be
the same size: the high-side fitting is always a smaller diameter line,
and the low-side fitting is in a larger diameter line. If in doubt, consult
the Vehicle Repair Manual and carefully follow the refrigerant path to
confirm each fitting.
CAUTION
LEXUS Air Conditioning and Climate Control - Course L752
The following chart describes the pressures in a fully charged system
given the ambient (existing) temperature in the test area. Because
humidity places a higher load on the A/C system, pressures will vary
within the range shown depending on the relative humidity. These
pressures also assume adequate airflow over the condenser: Position
an external fan to blow air through the front bumper opening,
particularly on rear-wheel drive vehicles with a belt-driven fan.
Ambient High Side Low Side High Side Low Side
Temp °F PSIG, HFC-134a PSIG, HFC-134a PSIG, CFC-12 PSIG, CFC-12
60 120-170 7-15 120-150 5-15
70 150-250 8-16 140-180 8-16
80 190-280 10-20 160-250 10-18
90 220-330 15-25 200-280 12-25
100 205-350 20-30 220-300 15-30
(These pressures are also listed in the Vehicle Repair Manual in metric
units of ° C and kg/cm2.)
It is normal for the gauge needles to fluctuate (change reading) as the
clutch cycles ON and OFF and the heat load changes, but they should
not swing wildly. In addition:
• If the test pressure is below the ranges indicated, this indicates an
undercharged system that cannot exchange heat efficiently.
• Normal low-side pressure along with a much greater than normal
high-side pressure indicates air in the system.
• When both pressures are above range, the system is overcharged or
insufficient air is flowing through the condenser.
• If both gauges show equal pressures in the 60-80 psig range, this
indicates a fully charged system with an inoperative compressor.
Additional conditions and specific component failures can be diagnosed
based on gauge readings as shown in the Vehicle Repair Manual.
• Correct refrigerant charge amount is listed both in the Vehicle
Repair Manual and on an underhood label, which also list the
correct compressor oil type.
The chart got messed up in the post. Look at the attached excel sheet
A/C Pressure Gauge Determines how much refrigerant is in the
system. It also provides a convenient location to attach other
service equipment to the system. Part of a Manifold Gauge Set or
built into a Charging-Recovery Station. Two gauges are connected
to the system; one for the low-pressure side and the other for the
high-pressure side. The gauges and hoses follow a standard color
code. The low side is blue and the high side is red. Each gauge
shows the pressure in that part of the system.
When part of a Manifold Gauge Set, the valves (marked Low and
High), allow one or both inlets to connect to a central passage (thus the
term manifold"). A third hose fitting is reserved for charging or
evacuating the system.
The center hose of a manifold gauge set connects to a refrigerant tank
for charging or to a vacuum pump for evacuating the system. Charging
the system must only be performed on the low-pressure (suction")
side. This prevents dangerous pressure from developing in the
refrigerant supply tank.
A/C Pressure
Gauge Connection
Note: Pressure gauges
are built into the latest
recovery machines.
The static charge (system pressure with system OFF) is also of value
when troubleshooting. The rule of thumb" is a 1:1 ratio on the gauge
reading; approximately 1 psig for every 1° F of ambient temperature.
Thus, on an 80° F day, the system should have approximately 80 psig
static pressure.
For your safety, ensure each hose is connected to the correct service
port in the system. On older CFC-12 systems, the two fittings may be
the same size: the high-side fitting is always a smaller diameter line,
and the low-side fitting is in a larger diameter line. If in doubt, consult
the Vehicle Repair Manual and carefully follow the refrigerant path to
confirm each fitting.
CAUTION
LEXUS Air Conditioning and Climate Control - Course L752
The following chart describes the pressures in a fully charged system
given the ambient (existing) temperature in the test area. Because
humidity places a higher load on the A/C system, pressures will vary
within the range shown depending on the relative humidity. These
pressures also assume adequate airflow over the condenser: Position
an external fan to blow air through the front bumper opening,
particularly on rear-wheel drive vehicles with a belt-driven fan.
Ambient High Side Low Side High Side Low Side
Temp °F PSIG, HFC-134a PSIG, HFC-134a PSIG, CFC-12 PSIG, CFC-12
60 120-170 7-15 120-150 5-15
70 150-250 8-16 140-180 8-16
80 190-280 10-20 160-250 10-18
90 220-330 15-25 200-280 12-25
100 205-350 20-30 220-300 15-30
(These pressures are also listed in the Vehicle Repair Manual in metric
units of ° C and kg/cm2.)
It is normal for the gauge needles to fluctuate (change reading) as the
clutch cycles ON and OFF and the heat load changes, but they should
not swing wildly. In addition:
• If the test pressure is below the ranges indicated, this indicates an
undercharged system that cannot exchange heat efficiently.
• Normal low-side pressure along with a much greater than normal
high-side pressure indicates air in the system.
• When both pressures are above range, the system is overcharged or
insufficient air is flowing through the condenser.
• If both gauges show equal pressures in the 60-80 psig range, this
indicates a fully charged system with an inoperative compressor.
Additional conditions and specific component failures can be diagnosed
based on gauge readings as shown in the Vehicle Repair Manual.
• Correct refrigerant charge amount is listed both in the Vehicle
Repair Manual and on an underhood label, which also list the
correct compressor oil type.
The chart got messed up in the post. Look at the attached excel sheet
#5
Lexus Fanatic
iTrader: (182)
u need a new servor motor. get the temp one.my car used to blow cold on the passenger and warm on the driver or cold on both sides. now i have both the mode and temp servor motor out so im doing them both. bought some used ones from a guy on here but they were bad to so come christmas and bonus check im gonna do both. im sitll driving around without glovebox on until i finish this install. im in the process of doing a write up on these with pics and all........
#7
Lexus Fanatic
iTrader: (182)
sorta... lol....
mine is having issues besides the norm so i have covered what u need to do but i havent fixed my own problems yet
here try this post i made
https://www.clublexus.com/forums/gs-...vo-motors.html
mine is having issues besides the norm so i have covered what u need to do but i havent fixed my own problems yet
here try this post i made
https://www.clublexus.com/forums/gs-...vo-motors.html
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