Description: The wiring harness includes a custom relay and circuit breaker installed in the enclosure of the fuse box (see photo). Installation is simple. Simply mount the relay hub on the fuse box cover using the hardware provided, then connect the power wire,ground wire, two ECM control wires, and plug the two fan plugs into a set of fan truck electric for GM 2005 or later. When FAN 1 starts correctly, both fans will be at low speed, and when both FAN 1 and FAN 2 are started, both fans will be on at high speed. Fan assemblies are only available for 34" wide radiators. If your truck has radiators of different widths, then you should also upgrade your radiators. .
