SPAL Single Fan 40amp relay wiring harness kit 185 degree on/165 degree off with Sending unit. SPAL electric fan wiring harness kits are a must-have when installing electric fans. Designed to safely integrate with OEM wiring, the SPAL kits feature a waterproof relay along with printed wires which aid in installation. The wiring kits also feature stainless steel switches with optional switched override capability, fuse holder, and wiring connectors.