Engine Coolant Temperature Sender - Standard Motor Products Part Number TS557

In design; we specify custom wax formulations that will expand when heated; activate a snap action electrical contact and transfer the electrical signal to the fan controller. In manufacture; we custom form the wax pellets for different temperature range specifications. All units are calibrated & tested to confirm switch actuation at their specified temperature. The switch is designed using a formed bimetallic contact arm. The bimetal contact movement is achieved using the different expansion ra