AC Prob Pressure Jumps From 15psi To 45psi Compressor Clicks Car Shakes Psi Falls Back To 15psi Not Cold
Posted in Air Conditioning | Asked on Feb 21, 2012
Below is the question about AC Prob Pressure Jumps From 15psi To 45psi Compressor Clicks Car Shakes Psi Falls Back To 15psi Not Cold, 1998 Ford Escort SE Wagon, R-134a refrigerant, says it takes .79kg (no idea what that is in psi?). Basically, my cars AC hasn’t been running in a year because of a faulty relay. I replaced the relay today. Only now, I have this problem: you can hear all of the components coming on now, only it still isn’t cold — the pressure in the low-pressure port will jump from 15psi to 45psi, the compressor will click (probably as a safety mechanism — 45psi is too high, maybe?) the car will shake, and the psi will fall to 15psi again, and then do this all over again. And again, it isn’t even cold. It sort of just leads me to believe that there’s either too much or too little freon in the car. The thing is, I can’t even get an accurate reading to know if this is the case as it keeps jumping from 15psi to 45psi — I can only assume the pressure is above 45psi, maybe? The pressure has been played with over the months — some has been taken out, some has been put in…
So question: what does it sound like my problem is? If it does sound like there’s too little/too much R-134a, which is it — too much or too little? ALSO, would I refill it while the AC’s on WHILE it’s jumping in pressure like this?
I all ready saved myself $300 by finding the faulty relay, myself — something a shop couldn’t even diagnose. I’d really rather try this myself, even if there is that chance of blowout, which I don’t think will happen.
There are 4 Answers for "AC Prob Pressure Jumps From 15psi To 45psi Compressor Clicks Car Shakes Psi Falls Back To 15psi Not Cold"
It sounds like your problem is you don’t know WTF you’re doing. You need to draw a vacuum on the system and then inject the correct amount of 134a by weight. I’d also recommend putting dye in the system so the leak can be traced. Too little refrigerant and the system cycles on and off. Too much refrigerant and you blow out the compressor. I’d recommend going to a qualified and certified AC mechanic and do the repairs legally.
Have to agree with the other guy. If you have no idea what .79 kg means and you are using one of those diy kits then the system need professional attention. The .79 kg is the amount of 134 in weight . And if you are only are using the cheap gage that came with the can , they really do not work accurately. You need a professional set of manifold gages that read both the low and high side. As stated to little causes cycling and to much causes a compressor to blow out. Take it in and have it done by a shop, save yourself some money.
You’re going to do more damage than good if you keep working on it without knowing the basics.
Perhaps you should do some research online before you continue, so you at least have a clue as to what you are doing.
Type into your search box “understanding automotive air conditioning.”
http://www.familycar.com/ac1.htm this one is pretty good.
I’ll join the chorus and tell you to seek experience.
Finding the relay problem was great but just putting refrigerant in willy-nilly and if you have too much you probably vent it out, which is illegal.
Trust me, unless you get really lucky, your AC will not work until you start with a overnight vacuum, then according to you it needs .79kg, which is 1.738 pounds of weight or
790 grams. BTW, you can’t convert weight to pressure, doesn’t work that way and the system needs a specific WEIGHT, by manufacurers directions.
Your gauge is worth what you paid for it.
You didn’t save $300 and you are going to end up spending more.
Edited: Because I just saw the decimal point.