air con low pressure switch??

i have a 90 300zx NA and the clutch wont engage on my aircon i have power to the relay and fuses and the only way i can get the clutch to engage is bypass the relay. i have a feeling its the low pressure swith but i dont know where it is or what it looks like. any help would bbe appreciated

 

Low pressure switch is on the receiver drier in front of radiator - refer FSM for testing procedure.

 

whats FSM? lol

 

Factory Service Manual - refer Tech Section

 

so i found my low pressure switch and it has power and as soon as i earth the power out the clutch engages. and if i bridge the plug out nothing happens so is there like something thats stopping it working?

 

Just a guess but maybe you actually have low aircon pressure ie you need to get your aircon regassed?

 

nah i put gas in it it thats how we found out the compressor wasn't working haha

 

Could have a leak and its empty again

temporarily bypass the low-pressure switch and see if it works. Ifso, then you either have a prob with leaking gas or the low-pressure switch faulty. Must get it fixed though. the low-pressure switch is there for a reason- to stop the compressor seizing from no gas (which has lubricant).

 

by bypass do u mean put a wire inbetween the two plgs bridgeing them together? cause i did that and nothing happened the only way i can get it to engage is earth the wire coming from the relay to the low pressure switch