AC works great on blower speed settings 1 thru 3 but on highest speed setting (4), the compressor stops and the AC "on" light goes out. This means there is no cooling when the blower speed is at the highest setting, but the blower is working properly. This is a factory installed AC system that is original equipment.
The two blower fuses check good and the AC fuse checks good. The AC condenser fan relay works properly when the compressor is running. With the blower speed set on the highest setting, that means the resistors are not being used.
After pulling the console panels off, the blower speed switch appears to be an integral part of an assembly which includes three levers (inside/outside air, heater temp, duct control). That means the blower switch is not replaceable as a single part. Not sure this is a switch problem.
Anyone had a problem like this? It is a 19 year old auto. What can I do next?