Hi there,
The low pressure switch should be at or near the receiver dryer, but what concerns me is that the comp should engage with the clutch hot wired regardless of system low pressure, depending on the compressor and system fitted the low pressure port should be on the compressor, A/C refrigerant should be added by weight and monitored by system pressure gauges, over filling the system can do serious damage to the compressor, tx valve and other internal components, I would highly recommend that you first have the integrity of the compressor checked out first as if it is faulty you will be wasting your time and money adding refrigerant.
Mark (mhpautos)
Sunday, April 18th, 2010 AT 11:13 PM