AC question

[G NASTY]

My Gn is all stock, last year I converted to r134 and had perfect working AC. Car is verrry low mile. I went for a spin yesterday and compressor won't turn on now. Compressor is not frozen, and system is full with 134. What could my issue be? Everything workes like normal(blower/HVAC unit) just no cold air. Thanks in advance

 

[pacecarta]

you say its full , without having the compressor running you cant verify that
odds are you are below 24psi on the low side and until the charge is brought up above that to activate the switch it wont run
jump the low side switch and see if the compressor will cycle and then you can read the charge pressure

 

[G NASTY]

Cool. How do I jump the low side switch?

 

[pacecarta]

remove the connector on the drier (rubbery round plug) and use a paperclip or whatever to jump the female spade terminals in the connector

dont drive around like that . check the charge pressure and go from there

hook a gauge to the low side port , engine running , ac selector on, blower on high and while the compressor clutch is engaged read the lowest pressure the charge drops to , if its below 24 the system needs more refrigerant,
if its over 25psi on the low pulldown the switch should have allowed it to engage the clutch and the switch could be bad

 

[G NASTY]

Thanks Paul for the help. According to the gauge I'm at 42 psi. what switch could be the problem?

 

[pacecarta]

did the compressor clutch engage when you jumped it ?

if so and you have 42psi on the low side replace the low side switch on the drier , it has a schrader valve in the drier so you should be able to quickly spin it off it to replace without loosing the charge
they have low switches designed for 134a

 

[hammer1918]

Your low pressure switch is probably bad.

 

[G NASTY]

did the compressor clutch engage when you jumped it ?

if so and you have 42psi on the low side replace the low side switch on the drier , it has a schrader valve in the drier so you should be able to quickly spin it off it to replace without loosing the charge
they have low switches designed for 134a

The clutch didn't engage.

 

[pacecarta]

if you read the first line i posted .......

if it didnt engage you dont have an accurate charge reading and if jumping the low switch didnt engage the compressor thats not the fault and i wouldnt go replacing the low switch

with switch jumped (engine can be off - key on) do you have 12v at the compressor clutch connector

if you have power the clutch is bad
if you dont have power at the clutch connector next inline is the ac cutoff relay on the passenger fender

 

[G NASTY]

If I have an inaccurate psi reading will jumping the switch still get it to engage? I don't have a test light to check power at the compressor.