A 12V wiper motor can draw less than 6 Amps of current. The exact current draw for a 12V wiper motor depends on its specific design, operational speed, and the load it experiences.
Understanding Wiper Motor Current Draw
The current a wiper motor draws is a critical specification for several reasons, including selecting appropriate wiring, fuses, and power supplies in a vehicle's electrical system. Motors typically draw more current under heavier loads or when starting up (inrush current). For a standard 12V DC electric wiper motor, the current consumption is generally specified as a maximum value under normal operating conditions.
Specifications of a 12V Wiper Motor
For a typical 12V DC electric wiper motor, key specifications provide insight into its performance characteristics, including its current consumption. Below are common specifications you might find for such a motor:
| Characteristic | Specification |
|---|---|
| Voltage | 12V |
| Noise | <55dB(A) |
| Speed Low | 28 +/- 3 RPM |
| Speed High | 45 +/- 5 RPM |
| Amp Draw | <6A |
This indicates that while operating, this particular 12V wiper motor will not exceed 6 Amps of current draw. The 'Amp Draw' specification often represents the maximum continuous operating current.
Factors Influencing Current Draw
Several factors can influence the actual current drawn by a 12V wiper motor during operation:
- Load: The primary factor is the load on the motor. A dry windshield or one with heavy snow and ice will present a much higher resistance to the wiper blades, causing the motor to work harder and draw more current.
- Speed Setting: Wiper motors often have multiple speed settings (e.g., low and high). The higher speed setting typically requires more power and thus draws more current.
- Motor Condition: An aging motor with worn brushes or bearings might operate less efficiently and could potentially draw more current, or conversely, less current if it's struggling to perform.
- Voltage Fluctuations: While specified for 12V, minor fluctuations in the vehicle's electrical system voltage can slightly affect current draw.
Practical Implications
Understanding the current draw of a wiper motor is essential for:
- Fuse Sizing: Fuses are vital safety devices that protect electrical circuits from overcurrent. A fuse rated slightly above the maximum normal operating current (e.g., a 7.5A or 10A fuse for a motor drawing less than 6A) is typically used for wiper motor circuits to prevent damage from short circuits or sustained overloads.
- Wire Gauge Selection: The wire used to power the wiper motor must be appropriately sized to handle the maximum current without overheating. Wires that are too thin can become hot, melt insulation, and pose a fire risk.
- Power Supply Capacity: If powering a wiper motor from an external power supply or considering the total load on a vehicle's alternator, knowing the current draw helps ensure the power source can adequately supply the motor without being overloaded.
