Suzuki TU250X Service Manual page 310

FUEL LEVEL INDICATOR LIGHT
Check that the fuel level indicator light immediately after turning
the ignition switch to "
If the fuel level indicator light does not light up, check the lead
wires, couplers, check relay and ignition switch.
CHECK RELAY (For fuel level indicator light)
• Remove the front seat and right frame cover. (8-3)
• Remove the check relay 1.
First, check the insulation between A and B terminals with the
multi circuit tester. Then apply 12 V to C and D terminals, + to
C and - to D, and check the continuity between A and B.
If there is no continuity, replace the check relay with a new one.
 09900-25008: Multi circuit tester set
 Tester knob indication: Continuity test ()
" position.
ELECTRICAL SYSTEM 9-29