2002-2007 Suzuki 500 LTA Service Manual, Page 322Get this manual

ELECTRICAL SYSTEM TROUBLESHOOTING Does not shift to 2WD4WD (2WD4WD motor will not run Turn on the ignition switchListen for
selecting button( 8-36) Correct Incorrect Faulty 2WD4WD selecting button Check the 2WD4WD selecting relay( 8-25 to 8-26)
Correct Incorrect Faulty 2WD4WD selecting relay Check the 2WD switch or 4WD switch8-36) Correct Incorrect Faulty 2WD switch