ive got a couple probs with my truck. first off every once in a while when i go to turn a corner my front end will start jerking like im in 4wd. its no though cuz when i step on it just the rear tires spin. second- when i turn just the blower fan on u can hear the a/c clutch kick on and off. whats causing these things?

 

Front end doing what your saying is usually a bad inner axle u-joint.

If your using the defroster the A/C compressor will kick on and off as it is supposed to work when you use it.If your talking just using the heat and the A/C compressor is kicking in and out then either you have a bad switch assembly or a vacum leak to the switch.