BT1-0541 Fan Relay Harness

The BT1-0541 Fan Relay Harness is engineered for use in mobile heating and air conditioning systems where controlled fan or blower activation is required. The harness features a pre-wired relay, integrated connectors, and color-coded wiring to reduce installation time and wiring errors in the field.

This harness uses a standard automotive relay configuration with clearly identified terminals (30, 85, 86, and 87), allowing it to be easily integrated into new builds or retrofit HVAC installations. The relay is housed in a compact enclosure with female plug connectors, providing secure electrical connections and protection from vibration.

Designed for durability, the BT1-0541 harness is commonly used in truck HVAC systems, off-highway equipment, and industrial cab applications where dependable fan control is critical.

Wiring & Electrical Details

Based on the harness drawing, the BT1-0541 includes the following wiring configuration:

• Relay Type: Standard 4-pin automotive relay (30 / 85 / 86 / 87)

• Relay Housing: Integrated relay block with plug connections

• Wire Colors & Lengths:

  • Red wire: 16 AWG, 16.75 inches long

  • Black & White wire: 14 AWG, 33.50 inches long

  • Orange wire: 14 AWG, 18.75 inches long

  • Black wire: 14 AWG, 5.75 inches long with ring terminal

The harness is designed to provide switched power to a fan or blower circuit, using the relay to isolate control and load currents.

Connector & Hardware Features

• Female relay plug connectors

• Ring terminal for secure grounding or power connection

• Pre-terminated wiring for quick installation

• Compact relay housing suitable for confined spaces

These features make the harness ideal for clean, professional HVAC wiring layouts.

Typical Applications

The BT1-0541 Fan Relay Harness is commonly used in:

• Mobile HVAC fan and blower circuits

• Truck and bus heating & air conditioning systems

• Construction and agricultural equipment

• Industrial cab climate control systems

• Custom or retrofit HVAC installations

Product Specifications

• BTRAC Part Number: BT1-0541

• Product Type: Fan relay wiring harness

• Relay Configuration: 4-pin (30 / 85 / 86 / 87)

• Wire Gauge: 14 AWG & 16 AWG

• Connector Style: Female relay plugs + ring terminal

• Assembly: Pre-wired harness