My car runs rough (vibrates alot more) when I use the AC.

Just saw this and thought I could offer some insight, as I have the same thing going on with my 2005 highlander. For me, I narrowed it down to a deteriorated bearing on the ac compressor. What I did was go to harbor freight, but one of their cheap "mechanics stethoscopes" amd used that. Surprisingly that tool has proved invaluable in pinpointing several issues across both of our vehicles. WARNING: when you put the ear pieces in, be VERY cautious about what you let the aluminum feeler piece contact, because if it bumps into anything hard (metal, asphalt, etc) it can be deafening.

Thank you for your answer. I took my car to get repaired and it was one of the fans in the cooling fan assembly. The bearings were bad in one of the fans. It cost $340.00 to replace the assembly, the part was around $200.00, so i felt like i got an ok deal. So much better than the compressor which one shop told me...total scam.