BMW Door Window Switch - Bosch 0343302003

Product Information

A door window switch is the electrical component that activates a vehicle’s window regulator motor to be raised or lowered. In most North American market European cars, the driver has a complex window switch that controls all 4 windows, and it is usually located on the driver's door. Some models of Mercedes Benz and Saab also have the window switches located centrally. The switches are usually simple, consisting of plastic buttons or toggles that connect to electrical contacts and are occasionally backlit for higher visibility.

Common failure modes of a door window switch include electrical contact wear, dirt or debris obstructing the switch mechanism, or internal circuitry failure. When diagnosing a faulty window switch, it's important to first rule out other potential issues, such as a failed window motor, blown fuse, or wiring problems.

If the switch feels loose or doesn’t click when pressed, it may indicate mechanical wear inside the switch. In cases where the window only works intermittently, the issue could be dirt buildup inside the switch or a loose connection, but more often intermittent window lift problems are related to the regulator and motor. A multimeter can be used to test whether the switch is properly sending an electrical signal to the motor. If the motor works when applying 12 volts to the motor connector, but the window doesn’t respond to the switch, it is likely the switch itself that needs replacing

• Window doesn't roll down: With enough actuation its likely that a switch will eventually fail, typically for the most used window. If the window has two switches, for instance, the driver switch pack and a rear door window switch, the other switch should continue to work. That’s a dead giveaway of a broken switch.
• Window operation is intermittent: If a switch is dirty or contaminated by crumbs or a spilled beverage, the operation could be intermittent. Apply 12v directly to the window motor, if it works as it should, the switch should be cleaned or replaced.
• Burned-out lights: In many European vehicles, the window switches will be backlit for easy night usability. Even in some modern luxury cars, the window switches may still use an incandescent bulb which of course can burn out. You can choose to try and replace the bulbs, but switches and switch packs are rarely serviceable and you would need to replace the unit to achieve appropriate lighting.

About Bosch

Bosch is one of the worlds leading suppliers of engine electronics and sensors. Their sensors and modules can be found in almost every modern car on the planet. Bosch Automotive offers a comprehensive portfolio of unmatched solutions for every job. From diverse diagnostic solutions and OE-quality auto parts, to industry-leading software and unmatched vehicle coverage, to innovative charging, repair and maintenance tools. Making repair and maintenance more effective, efficient, and sustainable for the vehicles of yesterday, today and tomorrow. With over 130 years of experience in the automotive industry, Bosch continues to lead the way in automotive innovation by inventing and developing quality products and solutions that focus on customer needs, shaping the future, and the continued pursuit of excellence.

Robert Bosch founded the “Workshop for Precision Mechanics and Electrical Engineering” in Stuttgart, Germany in 1886. Since the beginning Bosch has been a leader in innovation and development. They introduced fuel injection into mass production in 1967 laying the foundation for modern ignition electronics. Bosch brought lambda sensors to market in 1976, paving the way for cleaner exhaust gases and better fuel economy.

With millions of parts and products in their product line, Bosch offers everything from brake pads to household tools and medical supplies. FCP Euro has partnered with Bosch for the 2019 TC America Championship. They are a sponsor on our 2018 Volkswagen GTI TCR race cars. We offer Bosch's full line of OE and OEM components for your European vehicle.