A/C compressor and fan issue

ok i noticed today that for some reason when i stop driving and am just sitting in traffic, my AC  stop blowing cold air and was just luke warm air and then when i started moving again, it was cold again.  i have never seen that before so i decided to take a look at it when i got home.  well i let it sit idleing when i got home and popped the hood and found that my compressor is kicking on and off.  also i noticed that my secondary fan (A/C fan) never came on.  every car i've ever owned, the secondary fan came on as soon as you turn on the AC and stays on until you turn off the AC.  i'm just trying to find out what the "normal' operation of the AC on this car is.  i also have a weird rattling noise when my AC compressor is not on, and as soon as it kicks on, the rattle goes away.  the opposite of what i would think would happen if the compressor was going bad.  any input on this???

bump

The fan should turn on when the A/C is on, most of the time at least.
As for the noise, get a can of WD-40 and spray the hell out of every pulley you have, usually does the trick.

i have tried spraying wd40 on my pulleys.  i cant get it on some of them cause its a tight squeeze in front of them.  but do you think my compressor is on its way out the door?  since it makes noise and sometimes it stops blowing cold air and just blows luke warm air whenever i come to a stop for a few minutes

Make sure you have enough R-134A in the system.
Below 20 pounds/sq.in. the compressor clutch will
disengage.

is there a way to check the pressure in the lines?  or do i just need to get one of those recharge kits and just fill it up