Dear Boys: I posted 3 times for help and not one answer to my questions on 450sl 1977 aux fan . Repeated searches led me to your suggestions: How can I retrieve the info on by passing wiring and hook up direct on and off for aux fan? What checks to do on switch (location on thermostat housing?) or how to bypass switch for check? Any help after 4 days of no answers would be much appreciated. Regards, Abe G