A vehicle that is stopped stalls when the steering wheel is turned to full lock only when the air conditioning is on.
The power steering pressure switch signals the computer to increase the engine idle speed during parking-type maneuvers. If the vehicle has a bad power steering pressure switch, the engine could stall at idle when the steering is moved to the full lock position. This is due to increased load on the engine from the power steering pump.
Ram air flowing through the evaporator does not provide enough air flow inside the vehicle for cooling purposes. So, a blower is used to force the air along. An electric motor spins a fan, forcing the air into ducts, which direct it to the particular vent selected by the operator.
If the blower motor gets full voltage, it will run at high speed, but that is not always desirable. Therefore resistors are used to cut the speed down. The fan switch directs the current flow through one or more resistors to achieve the slow and medium speeds.
