03 Mustang Gt Ac Problems

To correctly diag an A/C problem, you're going to need to take it to a shop. There's just not a whole lot a shadetree can do.

If you really want to try and figure it out for yourself, you'll need:

1. A set of gauges (Harbor Freight and Parts store gauges universally suck, just buy what's cheaper in your area), and by set, I do not mean the bull**** low-side gauge that comes with some cans of R134a. You need to see what both the low and the high side are doing.

2. You'll need some R134a with UV dye (but no stop leak, if you put ANY kind of stop leak in your system, you're guaranteeing future trouble, and some shops will check for that first and refuse to work on the system after finding it.)

3. You'll need to find a shop that's willing to evac the system for you when you find the problem so you can safely, legally, and in an environmentally friendly way disassemble the system and replace the bad components, and then you'll need that shop or another to draw a vacuum on it after you're done making the repair(s) but before putting any R134a back in it so that you don't have any air contamination in the system.

4. A good understanding of how A/C systems work. (I should've put that first, but oh well.)

5. Some PAG oil in the correct viscosity or Esther oil and R134a.

If you don't have/aren't willing to get those five things lined up, take it to a professional. You can hurt yourself messing around with A/C, and you can hurt the A/C system further if you don't know what the hell you're doing.

I work on A/C systems in cars (as well as just about everything else in cars) for a living. I don't know a single technician that likes doing A/C work. Not a single one. We all like the paycheck from it, because if it's not a warranty job it pays decent, but tracking leaks on an A/C system, even with UV dye and/or a sniffer is a pain in the ass, and if the problem isn't a leak, we've got to try to coax the system into working long enough to see what the gauges do, listen for noises, etc. It's never really fun, because pretty much nothing but the compressor, orifice tube, and certain hoses are easy to get to on most cars.