Hello: I drive a 1993 Toyota Tercel with 130,000 miles on it. The car runs fine, but the A/C only works if I maintain a speed of 30 mph or more for several minutes. If I am driving in traffic, it stops working and just blows hot air. When I speed up again, it starts to cool again. I have taken it to the authorized Toyota dealer and when they run tests on it in the shop, it works fine. I live in Las Vegas, where the temperature can often top 110 degrees. It also works fine if the temperature is 80 degrees or less. What else could be wrong with it?
Puzzled.
This is a hard one because everything I suggest should have been checked by the people you took it to.
Have you taken the mechanic on a drive and shown him the condition? Does he see the problem but just shakes his head and says I dont know?
If no air is flowing over the condensor high side pressure gos’ up and performance goes down,but I am sure the mechanic would be checking airflow issues,I don’t know.
Perhaps excessive heat transfer from radiator.
When you turn the A/C ‘on’, are both of the fans running? You can check with the engine idling in ‘Park’. Open the hood and look – both should be working furiously. I would think that the Toyota service department would have checked that but omissions are possible.
Hope that is it.