Printed-Heater Lines Check

Run the engine at 2,000 r/min. Check the heater element with the battery at full.
Turn "ON" the rear window defogger switch. Measure the heater element voltage with an ohmmeter at the rear window glass center A. Condition is good if it indicates about 6 V.

Fig 1: Checking Printed-Heater Lines
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
If 12 V is indicated at A, there is a break in the negative terminals from A. Move the test probe slowly to the negative terminal to detect where voltage changes suddenly (0V).
If 0 V is indicated at A, there is a break in the positive terminals from A. Defect where the voltage changes suddenly (12 V) in the same method described above.

Fig 2: Identifying Characteristic Curve
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.