Keystone BM1550123 Rear Left Power Window Regulator Without Motor OEM Replacement

The Keystone BM1550123 is an OEM-style replacement rear left (driver side) power window regulator designed for the BMW X1 (2012–2015). This regulator replaces the mechanical assembly responsible for raising and lowering the rear driver's window and is sold without the motor, allowing you to reuse your existing window motor during installation.

Key Features:

• Direct OEM Replacement — engineered to match the fit, form, and function of the original factory part
• Driver Side (Left Rear) — specifically designed for the rear left door position
• Power Regulator, Motor Not Included — compatible with vehicles equipped with power windows; existing motor transfers to this unit
• OEM Cross-Reference: 51352990387 (also formatted as 51-35-2-990-387 / 51 35 2 990 387)
• Keystone Part Number: BM1550123

Window regulators are a common wear item. Signs of failure include a window that moves slowly, falls into the door, makes grinding or clicking noises, or becomes stuck in one position. Replacing the regulator assembly restores smooth, reliable operation. When installing, inspect the window guide seals for wear, as degraded seals increase friction and can accelerate regulator failure.