Hi Scotty,
2008 Toyota Sienna 3.5L 2GR-FE with 218,000 miles. My AC is blowing warm. Compressor is engaging and doesn't shutoff. Put the gauges on it and I'm getting about 20 PSI low side and 50 PSI high side at 71 degrees Fahrenheit. I'm thinking High side restriction or maybe bad compressor? How do tell the difference ? Thanks.
Looking at photos of that compressor on rockauto.com it appears that it has a control valve that would be operated by the computer. (There is an electrical connector shown at the rear of the compressor in addition to the connector for the clutch.) You would need a professional grade bidirectional scan tool to diagnose that.
A restriction in a line would result in a sudden temperature differential at the blockage point.
Or, it might just be low on refrigerant after 15 years.
Thank you for your post. I was initially hoping that it was just a low charge, but adding a bit of r134a did not help..... (I know I should recover what's in there and weigh it, but....) I guess I need to get the heat gun out and see if I can find a big temp differential, maybe in the condenser. Thanks again.