Fan kicks on and off every 5 seconds

[lorigail79]

I have a 2000 GMC Jimmy, 4x4. While idleing, the fan kicks on every 5 seconds. It kicks on, then off, then on, then off.... and it idles REALLY hard. Any ideas why the fan keeps doing this? It's been this way for atleast a year, but it's progressively gotten worse. Any help is appreciated!! Thanks.

 

[NuAge007]

does the A/C blow cold, i had my A/C unit overcharged and the clutch from the unit kept the fan going for quite some time, i have unhooked the a/c power and fan or clutch is not annoying my anymore.

will empty the a/c unit of freon (or actually have a tech do it) and recharge to proper pressure when it is needed.
the added stress to engine to keep a/c going made truck idle high and hard

the condensor has frozen up on me, but will still blow cold air if plugged in