1. Remove the seat warmer switch.
2. Inspect for continuity between the seat warmer switch terminals using an ohmmeter.
Drivers side
Passengers side
Mazda 6 Service Manual: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions (severe driving conditions) apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
...
Mazda 6 Service Manual: Accessory Sockets
Only use genuine Mazda accessories or the equivalent requiring no greater than
120 W (DC 12 V, 10 A).
Front
The ignition must be switched to ACC or ON.
Center
The accessory sockets can be used regardless of whether the ignition is on or
off.
CAUTION
To prevent accessory socket damag ...