The wife came home and told me that the car made a strange noise like a clicking/chattering noise at a low speed 25mph or so she turned the A/C off and it went away. I took the car out for a 20min run and the noise started about 10min into the drive. It sounded like a relay chatter and when I turned the A/C off it vanished again. I turned the A/C back on and it has not returned. Not sure what to look for, no codes and no other signs of a problem.

 

I had a similar problem in my old Mazda MX6GT. It turned out that a maple samara (the winged seed pod of the tree) had gotten sucked into the ventilation system through the vents at the base of the windscreen and was lodged against the back side of the interior vent vanes in the dashboard. It made an intermittent rattling sound until I found out what the heck it was. A quick grab with a hemostat did the trick.

Hope your problem is as simple. Good luck, Gus!

 

I always have a hemostat handy! You never know when you're going to have to surgically remove a maple samara or seal off a spurting artery.