I can't figure out my AC! Compressor will not stay on. It will cycle radomly, sometimes it stays on for 10-15 sec, sometimes just a few seconds. When is DOES stay on, the air is cold and the pipes sweat.

 

I did jumper the low pressure switch on the dryer and it made no difference.

 

Is this a high pressure issue? Like I said air is cold when it stays on. Is there a relay that could be failing? Car has 100K

 

thanks, Todd

Todd,

 

Any chance you've put a set of gauges on to see what the pressure is doing when the compressor is running? I'd try and start there to see if the pressures are normal. If so, then it's probably a bad switch or might be the temperature sensor in the evaporator.

What are the correct pressures? Low and high I know it varies with the ambient temp.

 

I believe the low is 30-40 and the high is 2.5X ambient temp when running.

Yeah....low side will typically be in the range of 30-40 psi and the high side probably around 200 psi or so....again like you said it's going to vary with ambient temp.