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K&n Air Intake Install & Now Ac Is Screwed Up

flytuc

By flytuc
in Ask A GM Technician

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flytuc Enthusiast

flytuc

Posted
Posted

Hello...

Just got through installin K&N Air Intake..All I did was disconnect neg batt terminal and unplug mass air flow sensor..Everything else was just physical tubing/gasket install..

Now with AC on, all I get is hot hot hot air blowing in defrost section only...NO AC and cannot switch to face forward blow or feet blow..Speed of fan works and controls on display show everything should be where it is, but not happening..

Please help...Anyone...WHAT HAPPENED??

Thanks,

Stephen

bill190 Enthusiast

bill190

Posted
Posted

Did you plug the mass air flow sensor back in? Is this also an IAT sensor?

 

If not plugged back in...

 

You can't just go and disconnect a sensor to the engine computer and expect things to work like normal!

 

In addition to the engine computer needing this information to make the engine run properly, the engine computer also has the option under certain situations to "turn things off".

 

For A/C, there is programming built into the engine computer to shut off the compressor under "dire" circumstances when more power is needed for the engine. Like wide open throttle. So maybe if you floor it while passing a car, the engine computer will shut down the A/C compressor until you are done passing.

 

Also if there are certain major malfunctions detected, the engine computer will "shut down" regular functions and go into "limp home mode". It has sort of a "backup" system which will allow the vehicle to basically function, but you are not going to get things like A/C to work. The engine computer would totally ignore requests to turn on things which are not necessary for basic running of the engine.

flytuc Enthusiast

flytuc

Posted
  • Author
Posted

IAT sensor?? I have no clue..MAF sensor was plugged back in...Rechecked & redid everything and now I can control where I want the air and AC comes on for about 20 seconds then instantly hot air...It makes sense what you explained about the computer...Is this somethig that is gonna cost mucho $...???

flytuc Enthusiast

flytuc

Posted
  • Author
Posted

FIXED....I unplugged the fuse one more time and tried again-nothing...I shut the AC off and the ignition...This time I turned the ignition to listen to anything unusual..Heard actuators working...Without turning on AC, I cranked the truck and then cut on AC, heard actuators again, Cold AC....Waitied....Still Cold AC....Waited some more...Still Cold AC...Shut off truck and restared several times---Still cold....Hope it lasts..

I just wanted to thank you for your input..Your explanation of the computer makes sense, that is why I tried what I tried..I figured the computer just reset itslef somehow..This is a great site...I just wish I could input more, I am just not that knowledgebale...At least this time I can give my experience with this problem again...

Thanks again to you...

Stephen

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