WARNING: This page is about a different car, the 2008 Suzuki Grand Vitara, 2007 Suzuki Grand Vitara, and 2006 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
Check for continuity across magnetic switch "S" terminal and "M" terminal. If no continuity exists, coil is open and should be replaced.
Fig 1: Checking Continuity Across Magnetic Switch S Terminal & M Terminal