LS 430 (2006) AC failure
Thread Starter
Driver School Candidate
Joined: Jun 2017
Posts: 24
Likes: 1
From: ON
LS 430 (2006) AC failure
The compressor is not engaging .There is no pulsed DC signal coming from the AC amplifier. First started as an intermittent failure. Then no AC and radiator fans not engaging at high speed. Checked compressor by applying 12V directly to control valve solenoid and compressor engaged and generated cold air. Short test as radiator fans not working to provide condenser cooling.
Replaced AC amplifier with used one from e-bay and it made no difference. Measured pin 5&6 Connector A11 measured 13 ohm same as value when measured at compressor solenoid. No voltage present at same pins engine running AC on (this model compressor is always on and cooling is controlled by varying the amount of compression internal ) No error codes on display panel (This is the base model no rear AC) High pressure valve 7.9 ohm outer pins and 4 inner. Ran vacuum pump on system and held vacuum -30 for several hours no leaks.
Note: Heat set temperature needs to be 28 or higher instead of 24 as in the passed. (odd)
AC relay tested good in fuse box #1. and all fuses I could Locate associated with AC system and they are all good.
Where to look next?
Replaced AC amplifier with used one from e-bay and it made no difference. Measured pin 5&6 Connector A11 measured 13 ohm same as value when measured at compressor solenoid. No voltage present at same pins engine running AC on (this model compressor is always on and cooling is controlled by varying the amount of compression internal ) No error codes on display panel (This is the base model no rear AC) High pressure valve 7.9 ohm outer pins and 4 inner. Ran vacuum pump on system and held vacuum -30 for several hours no leaks.
Note: Heat set temperature needs to be 28 or higher instead of 24 as in the passed. (odd)
AC relay tested good in fuse box #1. and all fuses I could Locate associated with AC system and they are all good.
Where to look next?
Racer
Joined: Jan 2004
Posts: 1,886
Likes: 456
From: North Carolina
Check the fuse box in lower left for water damage which causes a lot of problems. It would take an actual schematic to see what fuse is controlling the problem as many of them are associated with the system working. The radiator fans not coming on is another clue.
Instructor
Joined: May 2007
Posts: 807
Likes: 360
From: CA
The compressor is not engaging .There is no pulsed DC signal coming from the AC amplifier. First started as an intermittent failure. Then no AC and radiator fans not engaging at high speed. Checked compressor by applying 12V directly to control valve solenoid and compressor engaged and generated cold air. Short test as radiator fans not working to provide condenser cooling.
Replaced AC amplifier with used one from e-bay and it made no difference. Measured pin 5&6 Connector A11 measured 13 ohm same as value when measured at compressor solenoid. No voltage present at same pins engine running AC on (this model compressor is always on and cooling is controlled by varying the amount of compression internal ) No error codes on display panel (This is the base model no rear AC) High pressure valve 7.9 ohm outer pins and 4 inner. Ran vacuum pump on system and held vacuum -30 for several hours no leaks.
Note: Heat set temperature needs to be 28 or higher instead of 24 as in the passed. (odd)
AC relay tested good in fuse box #1. and all fuses I could Locate associated with AC system and they are all good.
Where to look next?
Replaced AC amplifier with used one from e-bay and it made no difference. Measured pin 5&6 Connector A11 measured 13 ohm same as value when measured at compressor solenoid. No voltage present at same pins engine running AC on (this model compressor is always on and cooling is controlled by varying the amount of compression internal ) No error codes on display panel (This is the base model no rear AC) High pressure valve 7.9 ohm outer pins and 4 inner. Ran vacuum pump on system and held vacuum -30 for several hours no leaks.
Note: Heat set temperature needs to be 28 or higher instead of 24 as in the passed. (odd)
AC relay tested good in fuse box #1. and all fuses I could Locate associated with AC system and they are all good.
Where to look next?
at pin 1&2 should be 10-11 ohms
Thread Starter
Driver School Candidate
Joined: Jun 2017
Posts: 24
Likes: 1
From: ON
More Diagnosis
Away for a while surgery.
How does the system know when there is not enough AC fluid in system.
There is no low pressure switch. Compressor type changed in 2004 no clutch
A component is disabling the signal to the compressor as well as the fans.
No water damage found fuses and relay all check out good.
Before total failure note on gauges low pressure side wildly swing from 40 to 20 psi.
Did not do this when refill earlier in the year.
Original leak caused by de-lamination of rubber hose low side.
I have also bought a Vac pump and run a vac test. no leak holds vac for hours.
I did see some water vapor boil of.
How does the system know when there is not enough AC fluid in system.
There is no low pressure switch. Compressor type changed in 2004 no clutch
A component is disabling the signal to the compressor as well as the fans.
No water damage found fuses and relay all check out good.
Before total failure note on gauges low pressure side wildly swing from 40 to 20 psi.
Did not do this when refill earlier in the year.
Original leak caused by de-lamination of rubber hose low side.
I have also bought a Vac pump and run a vac test. no leak holds vac for hours.
I did see some water vapor boil of.
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