To ensure power supply to power unit, disconnect primary wires connector at ignition coil. Turn ignition on. Using voltmeter, check voltage between coil positive terminal (Black/White wire) and ground. See Fig 1 . Battery voltage should exist. If battery voltage does not exist, check ignition fuse circuit.
To check power unit resistance, turn ignition off. Remove power unit from under ignition coil. Tape together two 1.5-volt batteries in series to create a 3-volt power source. Install leads to 3-volt power source. Apply negative lead to "G" terminal and positive lead to terminal IB of power unit. See Fig 2 .
Using ohmmeter, connect positive lead to terminal "G" and negative lead to terminal OC of power unit. See Fig 2 . Check for continuity with 3-volt power source applied to terminal IB. Check for no continuity with 3-volt power source disconnected from terminal IB. See POWER UNIT CONTINUITY table. Replace power unit if test results are not within specification.

POWER UNIT CONTINUITY

Application	Specification
3-Volts At Terminal IB	Continuity
No Voltage At Terminal IB	No Continuity

Fig 1: Testing Ignition Coil Power Supply (DOHC)

Courtesy of SUZUKI OF AMERICA CORP.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Swift (DOHC)