Pollak 21-477 Precision Ball Switch – Normally Open (N.O.) – Fits Weather Pack (WP) 12015792

The Pollak 21-477 Precision Ball Switch is a high-performance, Single Pole Single Throw (SPST) Normally Open (N.O.) sensor engineered for the rigors of the trucking and construction industries. This switch is designed to trigger critical vehicle systems only when the ball actuator is mechanically depressed, ensuring accurate and repeatable signaling for backup lights, neutral safety circuits, and PTO engagement.

What distinguishes the 21-477 is its specialized sealed terminal design, engineered to mate perfectly with the Weather Pack (WP) 12015792 connector. This configuration provides a watertight, dust-proof barrier that is essential for electrical components located in high-exposure areas like the transmission, transfer case, or lower chassis. By preventing moisture wicking and terminal corrosion, the 21-477 significantly reduces the risk of electrical failure and "green wire" rot.

Built with a rugged, zinc-plated metal housing, this switch is designed to withstand extreme vibrations, road debris, and corrosive chemicals. Inside, the self-cleaning "wiping action" contacts maintain low electrical resistance, ensuring a long service life even in 12V and 24V systems that undergo constant cycling.

Common Applications:

• Reverse/Backup Light Activation

• Neutral Safety Start Sensing

• Transmission Gear Position Monitoring

• Power Take-Off (PTO) Status Indicators

• Safety Interlocks for Off-Road and Agricultural Equipment