This harness adapter kit lets you specify the exact coolant temperature at which the electric coolant fan is switched on. This kit connects your vehicle's fan to your Accel harness and also uses OEM-style wiring and connectors for trouble-free installation and reliable operation. Using your PC or laptop computer and Accel's CALMAP software, simply enter the ECU Configuration section and type in the desired ''Fan On'' temperature. The ECU will store the number and automatically switch the fan on whenever this temperature is reached.