Brake Light Relay Inspection

Disconnect negative (-) cable at battery.
Remove brake light relay (1) from relay box.
Check brake light relay as follows.
1. Check that there is no continuity between terminals (5) or (6) and (4). If there is continuity, replace relay.
2. Check continuity between terminals (3) and (6). If there is no continuity, replace relay.
3. Connect battery positive (+) terminal to terminal (4) of relay.
4. Connect battery negative (-) terminal to terminal (2) of relay.
5. Check continuity between terminals (5) and (6). If there is no continuity, replace relay.
  
  Fig 1: Checking Continuity Between Brake Light Relay Terminal 5 And 6
  Courtesy of SUZUKI OF AMERICA CORP.