Automotive Air Conditioning Information Forum (Archives)

Provided by

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

air works intermittently

hkellogg on Wed July 29, 2009 7:41 AM User is offline

Year: 1996
Make: Gmc
Model: Jimmy
Engine Size: V6
Refrigerant Type: r-134a
Ambient Temp: 80
Pressure Low: 40
Pressure High: 150

working on a 96 jimmy and the problem is that the compressor does not turn on during certain instances...for example if I turn the car on while parked and the air is off then I turn the air on it won't turn the compressor on. But if I am driving on the road and turn the ac on the compressor turns on and starts too cool. I thought I might have a faulty low pressure switch but I do not, when the air is on the clutch is fully engaged and doesn't kick out at all. any ideas I would greatly appreciate it

NickD on Wed July 29, 2009 7:54 AM User is offline

I also work intermittently, blame that on my engineering job going to China and the economy for other forms of work, but stuff like you are running into seems to keep me plenty busy repairing the junk we have on the market.

Very common problem is that stupid press fit on your compressor hub, clutch gap widens so it doesn't always pull in, engine vibration at higher speeds help it. Need a special tool to close the gap to about 20 mils. I really couldn't comprehend your last statement, are you saying your compressor hub is running, but you are not getting cooling?

hkellogg on Wed July 29, 2009 8:02 AM User is offline

sorry about the misunderstanding, I was saying that once the air is on it blows cold and the clutch doesn't kick out at all its just a matter of trying to get the air to come on , secondly what kind of tool is it that I need to fix this problem

GM Tech on Wed July 29, 2009 8:51 AM User is offline

Next time you think it should be on- bump front of clutch with blunt object- see if clutch engages- higher mileage vehicles- tend to wear the air gap too wide- and the magnetic pull can't pull the clutch in across that wide air gap-- measure your air gap-- it needs to be at .020" to be good-- yours is probably .050+"

To fix you can "borrow" the tool from Autozone

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

NickD on Wed July 29, 2009 9:07 AM User is offline

is what it looks like, end screws unto the threaded shaft of the compressor then turn the outer nut that pushes the hub in while pulling on the compressor shaft closing the gap. Do this with a feeler gauge and slowly, if you push it in too far, than you have to switch the tool to pull it out again.

hkellogg on Wed July 29, 2009 12:25 PM User is offline

I tapped the clutch with a rubber mallet and it works so it must be the air gap gonna
grab the tool from autozone tonight just a question is that inches or millimeters I'm
checking because my feeler gauge doesn't do .020mm

HECAT on Wed July 29, 2009 12:36 PM User is offline



HECAT: You support the Forum when you consider for your a/c parts.


NickD on Wed July 29, 2009 4:04 PM User is offline

0.5 mm would be fine as would be 0.020 inches, or even adjust it at 20 mils. All the same dimensions, could also give that in light years, but man the zeros.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.