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2G AC Pulsing


Proven Member
Feb 27, 2022
Nashville, Tennessee
HI all, when I turn my AC on It pulses about once a second. I feel the pull on the engine with every pulse. Coldish air comes out but it's not cold enough to keep me cool in the southern heat.

I'm sorry if this has been answered before, I've been looking through threads and searching now for 30 minutes but haven't found the answer. I am Gen X so forums and tech comes a little harder for me.

Here is what I have done so far:
1. Checked the connections for anything obvious like exposed wires etc and found nothing.
2. Checked the pressure and added until it was good. Air got cooler but still not cold enough.

I've been blessed in the past with cars that have not had issues with AC any more than slight leaks.

I would appreciate any help or a link to a thread that could help me.
Last edited by a moderator:


Proven Member
Mar 2, 2011
fairfield, Virginia
Do you have a gauge set or was your 'checked the pressure' with the gauge on a 'DIY add some R-134a to your system' bottle?

Idling with the hood up and the A/C on full and recirc. can you hear the compressor clutch engaging, disengaging in time with those pulses? Engine speed going up and down a little? Fans coming on and going off?

There is a 'sight glass' -- a small round window on the top of the filter/dryer cartridge that's set in the left front fender, visible from above right behind the headlamp and forward of the power steering reservoir. Clean that window and see what you can see when your A/C is on. Does what you see change with the pulses?

You are probably going to need a professional to fix whatever's wrong but maybe we can get an idea from a few simple checks.


Proven Member
Feb 27, 2022
Nashville, Tennessee
Hey Waltah, thank you very much for answering this post.
I used a guage that is probably in the DIY category that you mentioned. It's a gauge that I bought separate from the bottle that uses the self sealing bottles that thread into it and it was like $50. I've used it on all my other vehicles and it's been working to get me cold AC on most of what I've used it on except the Eclipse but I suspect other issues with this thing.
I'm going to take the rest of the steps you've mentioned and I'll let you know how it goes.
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