QuestionQUESTION: I’m having trouble with my 2002 civic AC, and the issue is low pressure. After jumping the low pressure switch, the AC kicked in. When I shut down the car, there was a hiss coming from the blue low pressure line dust cap.
I had some work done on the AC last summer, and I’m assuming that the Schrader valve loosened, or possibly failed (not sure what the chance of that is). When I depress the Schrader valve, there is pressure in the line, just not enough to engage the AC I figure.
Would it make sense to try and tighten the low pressure line Schrader valve, and charge the AC with a kit?
From what I’ve read, you should charge (using a 12a kit) the AC when the AC is running. In my case, the AC doesn’t run because of the low pressure, so should I jumper the low pressure switch?
I’ve also read that low pressure when the AC is running should be max 40 psi. Is that true for a 2002 civic as well? Is there somewhere that I could confirm the specs? The Honda service manual doesn't seem to include the max/min pressure when the system is on or off.
Thanks in advance, I would appreciate some help.
ANSWER: HI Steven
On the Civic's you do not have a low pressure switch you have a high pressure switch on or near the drier. Your low side is relevant to the ambient temperature. So your low could be anywhere between 25 and 45 PSI depending on the temperature of the air. YOU can tighten your valve. But the most important thing is to put on the gauges and let me know the pressures. Your compressor will kick in with only 50 PSI any can of (134a) will have 80 to 110 PSI dependant on ambient temperature. Let me know and I'll try and help.
---------- FOLLOW-UP ----------
QUESTION: Thanks for your reply. I assumed the switch was a low pressure switch, given that it stops the compressor from running when there is low pressure in the system. Not important either way.
Assuming that I want to add 134a, are you able to answer my question related to jumpering the switch and what the max pressure should be? I do not want to overfill. Thanks.
AnswerThe low should be between 25 and 45 PSI the higher the temperature outside the higher the pressure. If you are about 80 degrees your pressure will be safe at about 35. If your is temp closer to 90 then your Psi will around 45. You can jump system but you need to take the readings high and low pressures. You can let me know and I'll help.
