Keep in mind the following

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Cable Terminal Inserted In Housing

Courtesy of VOLVO CARS OF NORTH AMERICA.

The secondary locking must always be open.

Inspect the locking tab/tabs on the terminal for damage and check that they are not pressed inward.

The cable terminal must be inserted from the housing's cable side.

Check against the wiring diagram that you have the correct cavity/position number.

Turn the cable terminal the right way up. Check against the other terminals.

When the cable terminal is inserted in the cavity a "click" is often heard when the primary locking engages.

Check that the cable terminal is firmly in place by pulling lightly on the cable.