Chrysler Repair: Climate Control Issues

Question
Mr. Finston,
I hope you are well. I have an issue with my climate control in my 2005 Sebring. Its a 4 door base model with the 2.4L.
A brief history on past issues and then what they have led up to/become:
The AC, several months ago, began blowing warm intermittently. It would blow cold for a while then randomly begin blowing hot. In the beginning, switching the setting from max ac to the defog setting would cause it to blow cold again. This went on for a couple months, as I couldn't afford to fix it at the time. Then, one random day, it stopped blowing cold all together. (Unfortunately in Texas in the dead of summer) we just stopped turning it on.  Then the weather began to change and it cooled down, so the issue went to the back of our minds. Well we had a warm snap and turned it on one day and to our surprise it blew as cold as I've ever felt it. So as of current, the air blows very cold, the heat works great, but there's one thing that has developed. Now, with the ac/heat/defog on, there is an intermittent sucking noise that almost sounds like a cheap cold air intake on a little tuner car. And each time it makes this sucking noise, it also clicks as if the compressor is clicking on. When this happens, the rpm drop significantly for a brief second, and if accelerating, you experience a brief loss in power, almost like u tap the brakes but not quite so dramatic.
I think this wraps it up. Sorry it is so lengthy. Any help you can offer would be greatly appreciated, as I would like to see the difficulty level of the repair and I may attempt it myself if possible. Thank you in advance!

Answer
Hi Ross,
The windshield defroster request actually does also actuate the AC compressor because cold air is able to remove the condensation better than warm air blowing on the windshield. If the sound seems to be coming from the engine compartment rather than from inside the HVAC unit, I would wonder if the compressor is perhaps beginning to develop a bearing problem which is causing it to put an excess drag on the engine output momentarily. Try asking for simple AC to the cabin with the temp set on the cool side and notice whether or not you get that same response when the AC clutch is activated under that condition. I can't think of any reason for the HVAC unit proper to put a drag on the engine. Another possibility besides the compressor bearing might be that the refrigerant level in the system is too low, but that usually is detected by the pressure sensor which then simply blocks the initiation of the compressor clutch entirely.
Let me know what you learn and we can try further if necessary.
Please read the PS below and respond to it.
Thanks,
Roland