Mazda 6 Service Manual: No.27 constant voltage

No.26 exhaust sulphur smell

No.28 spark plug condition

Other materials:

Mazda 6 Service Manual: Intermittent concern troubleshooting
  Vibration Method 1. If malfunction occurs or becomes worse while driving on a rough road or when engine is vibrating, perform the steps below. Note There are several reasons vehicle or engine vibration could cause an electrical malfunction. Some of the things to check for are: ...

Mazda 6 Service Manual: Interior Care
WARNING Do not spray water into the vehicle cabin: Spraying water into the vehicle cabin is dangerous as electrical devices such as the audio and switches could get wet resulting in a malfunction or vehicle fire. NOTE Do not wipe the interior using alcohol, chlorine bleach, or organic solv ...