Ground Circuit Checks
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Install breakout box and adapter. Connect adapter connector "A" to breakout box. Measure resistance between ground and breakout box terminals No. 13, 28 and 42. Ohmmeter should indicate about zero ohms at all terminals.