I have a dynamatic fan for a 46 ford I'm working on. This works ok on bench but will not activate on engine when running. I believe the thermostat/switch is not working properly. Does anyone know at what temps this fan is supposed to engage or disengage.I checked it with a volt meter and it doesn't activate till over 200 degrees. Also,anyone have a switch for the above fan for sale.This mounts in lower radiator hose.Thank you comried123@msn.com