what causes an A/C compressor to turn on and off at low rpms???

 

The pressure switch on the condensor could cause this at low RPM.
Thermal expansion valve perhaps too. If the lines get too cold compressor turns off to protect the system.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chrisw85 &raquo;</TD></TR><TR><TD CLASS="quote">The pressure switch on the condensor could cause this at low RPM. </TD></TR></TABLE>

yes, too low of an rpm can cause it to kick off and on. maybe to prevent stalling.

 

actually its suppose to engage the clutch on and off, depending on pressure. its perfectly normal for it to be cyling on and off, assuming you turned on your ac. for the low rpm, idling? or rpm drops while compressor turns on?

 

my a/c compressor is turning on and off constantly at idle/low rpms. this causes the motor to vibrate and act like it wants to stall. any idea whats going on?

 

its fast cycling...it is low on freon....if you have the ac or defrost turned on

 

my a/c is blowing cold. i did have my system recharged about a couple months ago but i'm not sure if its related. any other ideas?