90 compressor electrical problem or what?
Thread Starter
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
90 compressor electrical problem or what?
compressor wont engage on any C68 setting. However when power is applied to the blue compressor wire it has ice cold air and compressor seems to run normally.
All vent selector functions seem to work normally and no codes in the system. A/C fuse is fine, pressures are normal when compressor is running, .... any ideas?
All vent selector functions seem to work normally and no codes in the system. A/C fuse is fine, pressures are normal when compressor is running, .... any ideas?
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
Suggest a jumper wire in the low pressure switch electrical connector located in the low side line just in front of the evaporator housing.
Compressor runs = low freon or inoperative low pressure switch.
Ohm test the low pressure switch on the vehicle.
Open circuit = What is the low side pressure with the compressor running? 26# or more = replace the low pressure switch.
Switch has continuity = possible open circuit or poor connection in electrical connection.
Compressor does not run when jumper is connected in low pressure switch electrical connector.
Test the other wire (I think it is black) in the low side switch connector with a 12v test light.
No power = no signal from dash control head.
Has the radio been changed recently or has it been removed from the dash?
Compressor runs = low freon or inoperative low pressure switch.
Ohm test the low pressure switch on the vehicle.
Open circuit = What is the low side pressure with the compressor running? 26# or more = replace the low pressure switch.
Switch has continuity = possible open circuit or poor connection in electrical connection.
Compressor does not run when jumper is connected in low pressure switch electrical connector.
Test the other wire (I think it is black) in the low side switch connector with a 12v test light.
No power = no signal from dash control head.
Has the radio been changed recently or has it been removed from the dash?
Thread Starter
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
It has worked correctly before unless I am just missing something simple.
temp set to lowest setting
vent control set to auto
fan set to 10
even on windshield defrost the compressor still won't engage. One thing there is something unplugged in the center of my dash pad. The climate control seems to work perfectly though as in inside and outside temps.
I did try bypassing the lowside pressure switch and the compressor still would not come on.
radio is the bose
Pro
Joined: Oct 2006
Posts: 734
Likes: 0
From: Bryan Texas
After a little research, I now believe the compressor is always grounded, not always with 12 volts (like my 89). The 12 volts is switched on and off, turning your compressor on and off.
Check for 12 volts in the light green wire at the clutch relay when the compressor is supposed to be on, if you have 12 volts there, check for 12 volts before and after the high pressure cut out switch, if 12 volts there, check for 12 volts before and after the low pressure cycling switch.
These tests should narrow things down a bit.
Check for 12 volts in the light green wire at the clutch relay when the compressor is supposed to be on, if you have 12 volts there, check for 12 volts before and after the high pressure cut out switch, if 12 volts there, check for 12 volts before and after the low pressure cycling switch.
These tests should narrow things down a bit.
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