WARNING: This page is about a different car, the 2001 Subaru Outback and 2001 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Check continuity between terminals (indicated in table below) when terminal No. 4 is connected to battery and terminal No. 3 is grounded.
Fig 1: Front Fog Light Relay Continuity Chart
Fig 2: Identifying Front Fog Light Relay Terminals