Ticking tick noise from rear AC blower

[chalissery]

I have a 2010 Explorer which emits a 'relay like' tick tick noise from the rear left of the cabin, from the area close to rear AC blower.

AC is generally weak too.

What is causing this problem. Can this be connected with low cooling of the AC system?

 

[Bazz270]

Low r134 pressure.check for leaks and recharge the system