TechASSIST: Window Lift Regulators

ELTA Window Lift Regulator

Demand Continues to Rise

Aftermarket demand for window regulators continues to grow year-on-year because, as well as now being a generally standard feature, the trend for larger windows in modern automotive design puts them under increased stress. Here we look at the causes of failure, effective fault diagnosis and key considerations when replacing window lift regulators.

What goes wrong?

The winter will have taken its toll on window regulators across the UK as windows frozen in place put serious strain on both the motor and mechanism, especially as drivers hang on the power button to release them. The last year’s hot summer will have made window rubbers brittle, the freezing temperatures then expose the flaws allowing water through and into the door. This causes corrosion and eventually contributes to the failure of the mechanism. 

Correct Diagnosis 

Stripping down a modern interior door panel is by no means a quick job, but thankfully it’s possible to get a good idea of what might be going wrong by listening carefully for clues. If the motor can be heard turning, but the window doesn’t operate for example,it will generally be the mechanism that has failed. A grinding or clanking sound is also a giveaway that the mechanism is broken. If however, there is no noise at all, then the motor may be at fault. Nevertheless, always check the fuse and the switch before arriving at this diagnosis. 

Comfort function 

Cars with comfort function allow the windows to be completely raised or lowered at the touch of the button, rather than having to hold the it down. Many now also incorporate an ‘anti-pinch’ safety feature to prevent fingers, arms or even heads being trapped in the window. The important thing to remember is that the comfort function is associated with the window regulator, not the motor, so if the motor is still working, it is likely that only the mechanism will need replacing.

Fitting tips 

Following window regulator replacement, the one touch operation will sometimes not function as expected. This is because the vehicle needs to be recalibrated in order to understand the limits ofthe open and closed window. The most common method to initiate calibration is to ensure that the window is fully closed and then press and hold the window up button, for three seconds.

Many replacement bowden and double-bowden window regulator mechanisms that use cable to control the window will have a tensioner in place to protect the part during storage and transportation. This is usually a cable tie looped around one of the winders to preventing its rotation, that must be removed before operating the new part. 

On occasion, additional parts or wiring adapters may be required to fit the aftermarket regulator. If they are needed, window regulators will come with these parts included in the box. So, whatever is in the box, must be fitted.