Clicking Mustang

Hi, all!

My 2003 Mustang convertible (6cyl) has recently started making a loud clicking noise under the hood that seems to come on after driving in stop-and-go traffic or when turning on the a/c. I don’t notice it when driving on the highway at a relatively steady speed. The clicking will continue for a minute or so and then stop for a while. I had also noticed a strange melting plastic or chemical smell coming from under the hood whenever clicking has happened. I had also noticed a couple weeks ago that at stop lights, the a/c was blowing warm air even when on the coldest setting. The air would then become cold again after driving for about a minute.

What could this problem (or problems) be and can I fix it (or them) myself?

could be low on refrigerant and the A/C compressor is cycling on and off rapidly (the clicking you’re hearing).

I am fairly sure that the clutch on the A/C compressor is the culprit.
The burning smell is most likely the clutch material.

Just be aware that when the compressor clutch seizes (which is likely to be…any time now), there will be unforeseen consequences, as the drive belt will begin to slip, and it may break. That drive belt likely also powers the power steering pump and the alternator, so unless you relish being stranded with a dead battery and inoperative power steering, I would suggest that you have the A/C compressor clutch looked at…tomorrow.