Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2021 Mazda CX-3 AWDFACTORY OEM SERVICE PROCEDURE

Rear Window Defogger Inspection

Switch the ignition ON (engine off).
Turn the rear window defogger switch on.

Courtesy of MAZDA MOTORS CORP.
CAUTION:
- Directly touching the rear window defogger with the lead of the tester could damage it. Wrap aluminum foil around the end of the lead and inspect the rear window defogger by touching it with the aluminum foil.
Connect the positive lead of the tester to the positive side of each rear window defogger and the negative lead to ground.

Gradually slide the positive lead from the positive side to the negative side and verify that the voltage decreases accordingly.

Courtesy of MAZDA MOTORS CORP.

If the voltage changes rapidly, the rear window defogger has a malfunction. Repair the rear window defogger. (See REAR WINDOW DEFOGGER REPAIR .)

MEASURED PART AND VOLTAGE DESCRIPTION

Measured part	Voltage (Reference)
(1) to (2)	Approx. 11 V to 0 V

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready Tools Compare Repair Quote Quote Shield Pro

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.