Frequently Asked Questions（FAQs）

What is parking position?

When viewed from outside the vehicle, the wiper arm and blade must travel in a clockwise or counterclockwise direction to park, referred to as clockwise to park (CW) or counterclockwise to park (CCW).

Why do wiper arms and shafts have so many interfaces (i.e. knurl, drum, tapered knurl, DIN)?

Over the years, mainstream manufacturers have developed their respective standards for wiper arms.

Drum interfaces were widely used in automobiles during the 1950s and 1960s.
Tapered knurl designs are commonly seen in numerous off-road applications, as well as in larger vehicles like motorhomes and buses.
The European DIN standard, as the most recently adopted global interface, is applicable to all types of equipment.

What circuit protection should I provide my wiper motor?

12 V DC motors typically draw around 5 amperes during normal operation. This current draw will increase under heavy snow or wind loads.

For a single 12 V DC motor, we recommend a 10 amp circuit breaker; a two-motor system requires a 15 amp breaker.
For 24 V DC motors, use a 5 amp breaker for one motor and a 7 amp breaker for two motors.

Can I use a rocker or toggle switch with my self-parking wiper motor?

Yes, this is feasible when using a one-speed coast-to-park motor.
For two-speed coast-to-park motors, you may use a toggle switch exclusively on the low-speed setting.
Wire the park circuit to a "hot" connection through the ignition switch directly.
Employ a single-pole, single-throw switch to power the low-speed brush.

IMPORTANT NOTE: Never use a toggle or rocker switch with the high-speed setting on two-speed motors!

Which wiper motor should I use?

Wiper motors are rated by stall torque, typically expressed in Newton-meters (Nm).

A 38 Nm motor is recommended for arm-blade combinations of 28” (710 mm) and longer, as well as systems with multiple arms/blades driven by a single motor.
A 30 Nm motor suits arm-blade assemblies ranging from 20” to 28” (500 mm to 710 mm).
A 12 Nm motor is appropriate for 16” to 20” (400 mm to 500 mm) arm-blade configurations.
An 8 Nm motor is optimized for small arm-blade setups of 16” (400 mm) or smaller.

Notably, motors with 20 Nm or less stall torque often incorporate internal linkages to generate the required oscillating motion.

What’s the difference between coast to park and dynamic park motors?

Coast to Park Motors

When switched off, the motor "coasts" to a mechanical stop. The park position of coast-to-park motors may vary by several degrees.

Dynamic Park Motors

When powered off, the motor electrically locks into the park position. Dynamic park motors ensure consistent park positioning at all times.

Which sweep pattern is best for my application?

Radial Wipe Pattern

Ideal for glass surfaces where width exceeds height, the radial pattern utilizes pivot points positioned close to the window. This design generates arcuate wiping trajectories, optimizing coverage for wide-aspect glass by leveraging radiating motion from the pivot.

Pantograph Pattern

Suited for tall, narrow glass, the pantograph pattern employs pivot points set farther from the window. Driven by a linkage mechanism, this configuration enables parallel wiping motion, ensuring vertical coverage efficiency through synchronized arm articulation.

For technical comparisons—including trajectory mechanics, pivot geometry impacts, and application scenarios (e.g., commercial vehicles vs. passenger cars)—refer to illustrative case studies on radial vs. pantograph sweep dynamics.

How should I measure wiper arm length?

Wiper Arm Length Designation Nuance

It may come as a surprise that the physical length of a wiper arm exceeds its specified industry length. This discrepancy arises because the standard practice defines wiper arm length as the straight-line distance from the pivot shaft center to the wiper blade connection center—not the actual arm extrusion length.

For technical clarification and a visual demonstration of this measurement convention, refer to our detailed guide: How to Measure Wiper Arm Length, which illustrates the geometric definition and practical measurement methodology.