Circuit Description
WARNING: This page is about a different car, the 2003 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
The integration control and panel outputs the magnetic clutch ON signal from terminal AC1 to the ECM. When the ECM receives this signal, it sends a signal from terminal ACMG and switches the A/C magnetic clutch relay ON, thus turning on the A/C magnetic clutch.