RAD FAN issue? Clicking from intake? PLEASE HELP

[m7a7c7]

2005 Moon & Tune: I noticed that my RAD fan wasn't coming on when I turned on the defrost anymore. This is new. Is this something that is a normal, common easy fix (relay, fuse, ect.) Are there any tests I need to run?
When I was poking around under the hood I noticed a clicking coming from a sensor/relay mounted above the air box. It seems to be clicking constantly. This can't be right! That should wear sensor/relay out quickly. Does anyone know what that is?
Please help if you know the answer. Thanks in advance!

[Chiadog]

When my AC/Defrost went out, it was the fuse labelled (COOLING FAN?) under the hood. AC relay may cycle in DEFROST with a blown FAN fuse. This is just my guess, but check your fuses. If the fan fuse "LOOKS" good, pull it out and test it!
chiadog

[m7a7c7]

When my AC/Defrost went out, it was the fuse labelled (COOLING FAN?) under the hood. AC relay may cycle in DEFROST with a blown FAN fuse. This is just my guess, but check your fuses. If the fan fuse "LOOKS" good, pull it out and test it!
chiadog

Thanks 'dog! I will check into it on my lunch break. Thanks for the response.

[m7a7c7]

bumpdate I did check the fuse for the rad fan and it looked great. the fan came on two times today. I kept the heat selector on defrost the whole time. Sometimes it works sometimes it doesnt. When the fan isnt working I dont hear the click from under the hood like I used to. When the fan is working it does click. is there a relay for this operation, and where is it located? thanks in advance.

[Chiadog]

I agree with johnO in your other thread; possible low refrigerant charge or below freezing temperatures. Check the AC refrigerant charge. Clicking is likely the AC solenoid - click ON from demand, click OFF from low refrigerant pressure, etc.