System Relay Power Supply
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1984 Volvo 245, 1984 Volvo 244, 1984 Volvo 242, 1983 Volvo 245, and 1983 Volvo 244. However, it is still accessible from the selected car via links, so may be relevant.
Connect voltmeter between ground and terminal 9. Ground terminal 21. Relay should switch on and meter show battery voltage.