Engine cooling fan always on when running, a/c-recirculation 3 blink

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tomustang

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Engine temp is fine, a/c ran super cold 1 day ago.

Day later I started the car, 85° outside, noticed the cooling fan started running, once I got into yukon I tried the a/c and the light blinked 3 times and shut off, same happened with the recirc. I tried the other controls and the only selection that works is Auto. The defrosters work fine but can select anything besides Auto.

All air that comes out of vents is hot.

I cannot find any other search inquires that deal with engine fan constantly running and the AC / recirc blinking.
 
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tomustang

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Update.


I ran a 12 power source to the a/c compressor while the motor was on, the clutch engaged and i got cold a/c.

AC and recirc button still flashing 3 blinks, assuming now that the wire going to the AC compressor is bad and the engine is reading that it's non-functioning so the high-speed fans are running.

Freon level was full, thermostat is new, coolant sensor on block is new. A/c sensor on canister is new. A working relay was checked and got nothing.

I'm going to trace the wire to see if there's any breaks in the line.
 

thompsoj22

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There are alot of troubleshooting vids on youtube dealing specifically with your issue and how to isolate it. recently i purchased a "DESLUGGER" from 4 seasons ac to eliminate the compressor slugging which i have experienced twice. our low mounted compressors are susceptible. have you checked for 12 volts and ground at the ac connector to the compressor? simply remove the connector to the compressor hook up your meter and cycle ac on/off. the pressure switch on the dryer will also prevent ac clutch engagement.
 
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tomustang

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have you checked for 12 volts and ground at the ac connector to the compressor? simply remove the connector to the compressor hook up your meter and cycle ac on/off. the pressure switch on the dryer will also prevent ac clutch engagement.


Since you said the compressor plug, I just checked it both with running and not and I get no power. The relay side is fine.
 

Joseph Garcia

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The three blinks of the AC light indicates that the AC mode is not available.

From the owner's manual:

#(Air Conditioning): Press this button to turn
the air conditioning (A/C) compressor on and
off. When air conditioning is selected, an indicator
light will come on to let you know that the air
conditioning has been activated.
Pressing this button when the outside temperature
is too cool for air conditioning will make the air
conditioning indicator flash three times and
then turn off to let you know the air conditioning
mode is not available
. If the air conditioning
is on and the outside temperature drops below a
temperature which is too cool for air conditioning
to be effective, the air conditioning light will turn off
to let you know the air conditioning mode has
been canceled.

I recognize that the too cold outside air scenario is not your current scenario, but you may be able to troubleshoot the system to see what other conditions could make the truck's computer think that it is too cold outside.
 

scrtcell

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Hey I know this may sound like a long shot and some things may not seem so obvious only because I have seen this before but is the belt missing that drives only the compressor ijs
 
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tomustang

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The three blinks of the AC light indicates that the AC mode is not available.

From the owner's manual:

#(Air Conditioning): Press this button to turn
the air conditioning (A/C) compressor on and
off. When air conditioning is selected, an indicator
light will come on to let you know that the air
conditioning has been activated.
Pressing this button when the outside temperature
is too cool for air conditioning will make the air
conditioning indicator flash three times and
then turn off to let you know the air conditioning
mode is not available
. If the air conditioning
is on and the outside temperature drops below a
temperature which is too cool for air conditioning
to be effective, the air conditioning light will turn off
to let you know the air conditioning mode has
been canceled.

I recognize that the too cold outside air scenario is not your current scenario, but you may be able to troubleshoot the system to see what other conditions could make the truck's computer think that it is too cold outside.

I ended up testing on them both yesterday, I swapped them around and I still had outside temperature readout so I know they're both fine.
 
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tomustang

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Hey I know this may sound like a long shot and some things may not seem so obvious only because I have seen this before but is the belt missing that drives only the compressor ijs

There's a new belt on it, I've already jumped the compressor with an outside 12v source and it blows cold air inside
 
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tomustang

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I've bought another AC sensor to see if the other one was bad.


Does anyone know if they're supposed to be constant power going to the AC compressor, because I'm not getting any juice, I don't know if the reason why the fans are on if it's cutting the power to the compressor or not
 
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