01 Jimmy A/C dies under load

[km2002]

Never seen this problem before; can't find any reference to it on this forum (manually checked about 25 pages in addition to searching for A/C related posts), or anywhere else (such as AllData) for that matter. Have an 01 Jimmy, 4.3L. The A/C starts to die under load, typically when I'm climbing hills. Air volume drops precipitously, temperature feels like it's going up (air temp as well as mine). Haven't found any reference that makes the connection. My first guess is that I need a recharge; haven't been able to test that assumption. Open to suggestions. Thank you one and all.

[MT-2500]

Originally Posted by km2002

Never seen this problem before; can't find any reference to it on this forum (manually checked about 25 pages in addition to searching for A/C related posts), or anywhere else (such as AllData) for that matter. Have an 01 Jimmy, 4.3L. The A/C starts to die under load, typically when I'm climbing hills. Air volume drops precipitously, temperature feels like it's going up (air temp as well as mine). Haven't found any reference that makes the connection. My first guess is that I need a recharge; haven't been able to test that assumption. Open to suggestions. Thank you one and all.

Describe AC strats to die under load.
What is the vent tempture at idle and at 2K rpm?
When AC starts to die under load does the vent tempt rise?

ACTING UP UNDER LOAD POINTS TO VACUMN PROBLEMS.

Check for full engine vacumn from engine to ac controls.
Like all lines and fittings and rubber and plastic hoses and fittings and vacumn tank if it has one.
Auto or manual ac controls?

[km2002]

Thanks for the response, MT-2500. Manual controls. Guess I need to get a thermometer to measure the temp; just been going on what it feels like in the cabin. Otherwise, thought I'd described "A/C starts to die under load" fairly well; aside from suggested problem areas, don't know what else you'd like to know. I do know that a vacuum problem reared its head about a month ago as the reason my service engine light came on; that was corrected and has not recurred.

[MT-2500]

Originally Posted by km2002

Thanks for the response, MT-2500. Manual controls. Guess I need to get a thermometer to measure the temp; just been going on what it feels like in the cabin. Otherwise, thought I'd described "A/C starts to die under load" fairly well; aside from suggested problem areas, don't know what else you'd like to know. I do know that a vacuum problem reared its head about a month ago as the reason my service engine light came on; that was corrected and has not recurred.

Double check for full engine vacuum from engine to ac controls when under load and also confirm good engine vacuum at 2K rpm.