WUR Micro-Switch Question
 

On a 1975 911s with a 2.L engine I have read many posts concerning the throttle body mounted micro-switch. When starting cold most say to lift the throttle lever to engage the micro-switch, however on my car when the accelerator is at rest, "not pressed", the arm on the throttle body is not touching the switch. By lifting the lever it moves farther away. I guess I could take an ohm meter and see if it is normally open or closed. But in my mind, if it is normally closed then the circuit to the temperature switch on the chain case would be the true control.In all I have read about this system I still am not clear on its correct operation. Any help appreciated. TIA Jim

The power for this circuit is the same as the starter, it is only powered when the key is in the start position. The switch is open when the arm presses down on it. This way it has no power in a warm start situation. When the arm is lifted off by the cold start lever, power is sent through the circuit when you start the car, enabling the cold start solenoid. The Thermo time switch is a control in the system, although they did not use one in my 1973.5.
You should adjust the arm so that it contacts the switch.