2005 Corolla AC Problems

[beeson76]

The AC compressor will kick on and shut down almost immediately. What could be the problem. It will kick on for about 15 seconds then shuts down for about 1 minute and then repeats the cycle. It kinda acts like it is low on Freon. But it has plenty of Freon. I can feel the pipes getting cold.

We are looking into it being the AC Clutch Relay. Do you think this could be the problem.

Also the pressure on the low side is about 50 psi. Could someone please let me know if this is too high. I cannot find anywhere where the low side pressure should be. Could someone gives the low side pressure or a range that it should be in.

Thanks.

[mikered30]

low side is too high. 25-40 psi on the low side and 200-250 on the high side, depending on the outside temp.

[beeson76]

After doing more testing here is what I have come up with. At slow speeds the AC compresser works fine and pressure is about 38 pounds on the low side. The AC feels cold. At high speeds the compressor shuts off completely after a short while. It will then come back on with about 28 pounds pressure (again on low side). Then it will kick off again after a short while.

Does anyone know what could be causing this.

Thanks for any help provided.

[John Anthony]

If it's more than 90 degrees outside, then low side at 50 PSI is not too high. At least, that is what my chart shows. Anything over 55 PSI at that temperature or above is too high (according to the chart). Check an ambient temperature chart and look for the appropriate pressure at your ambient temperature just in front of the condenser. It's important to check the high side pressure as well. This will tell you if you have a problem with your expansion valve. As Mikered30 said, high side should be 200 - 250 PSI. Also, to get accurate guage readings, they should be done after 10 minutes of the system being engaged with the guages connected (although yours may not engage for that long, I understand). Also, FYI, if you want to replace your A/C relay it will cost you about $70 from Toyota, but if you use a Honda relay (which fits/works perfectly) it will only cost less than $10.