Troubleshooting: Power Windows

Automotive master window switch.

A power window that moves slowly and the switch must be pressed several times to move the window up or down may have a faulty circuit breaker. A self-resetting circuit breaker resets itself.

A blown fuse element creates an open circuit until its replaced. An open anywhere in the circuit results in no operation of the window. This fact omits an open window switch or fuse as a possible cause because the window would not move with an open circuit.

Automotive power window motor and regulator.

This problem could be electrical or mechanical. Self-resetting circuit breakers are often used in place of fuses in window circuits because they serve two purposes. They not only protect the circuit from overload but also open the circuit when the window seats into the window frame or the base of its travel.

When there is a circuit overload caused by a faulty gasket, motor, or regulator the circuit breaker opens from the excessive current, cools and allows the motor to temporarily move the window just a little bit until the breaker heats up and opens again.

Window Gaskets

The window fits snugly into the window gasket. If anything interferes with its movement or if there's a kink in the gasket, the window drags. Silicone is often used to make a window run or weatherstrip more pliable.

Circuit Breakers

Some circuit breakers need to be manually reset by removing them from the power source or pressing a button. Most circuit breakers are self-resetting. Today's circuit breakers are solid-state ECB's. These circuit breakers increase resistance as they heat from excessive current. They can overheat and prevent the window from operating.

Blown Fuses

When a fuse is overloaded, and too much current is passing through, the element melts creating an open. They do not reset like circuit breakers and must be replaced to complete the circuit. It's important to rule out any component or short circuit that may be causing the fuse to blow. Sometimes fuses blow from a temporary overload caused by icy windows and such.