lss ac

[crobinson442]

i have a 1998 lss with no freon the ac worked i changed the hose anw the clutch wont kick on to take the freon.how do i jump the switch and where is the switch located?

[crobinson442]

any advice

[BNaylor]

Originally Posted by crobinson442

any advice

Are you referring to the low pressure switch?

[regalfriend]

How many PSI did you read while trying to charge? A/C can be PITA. The low pressure switch BNAYLOR mentioned is there to prevent your compressor from burning out when you have low pressure.

[BNaylor]

Originally Posted by regalfriend

How many PSI did you read while trying to charge? A/C can be PITA. The low pressure switch BNAYLOR mentioned is there to prevent your compressor from burning out when you have low pressure.

Thats true and I believe it also serves as a high pressure switch. The problem is the reference voltage of around 5v feeding the pressure switch comes from the PCM module. The pressure switch varies its electrical signal going back out to the PCM depending on line pressure. Unlike older AC systems the switch cannot be arbitrarily jumped to get the compressor to kick in. A resistor of the proper value overcoming the low voltage and high voltage threshholds must be used, otherwise the PCM commands the compressor off.

If the refrigerant is zero, it is better to have a HVAC Pro do a proper evacuation and charge of the system.