R

RANDOM ACCESS MEMORY (RAM) - A type of memory which is used to store information temporarily. Information can be written to and read from RAM.

READ - A microcomputer operation where information is retrieved from memory.

READ ONLY MEMORY (ROM) - A type of memory which is used to store information permanently. Information can not be written to ROM; as the name implies, information can only be read from ROM.

READOUT CONTROL - Circuits inside of the ECA that are used for operating digital instrument displays.

RECHARGE - (1) To restore energy to a battery by means of an electric current. (2) To restore the level of a substance in a system, as recharging an air conditioner with refrigerant.

RECTIFIER (diode) - Electrical device that permits alternating current to flow in only one direction thereby transforming it into direct current.

REDUNDANT BRAKE SHUTOFF - A safety feature of Ford speed control systems that shuts the speed control system off if there is a 10-15 mph drop in speed.

REFERENCE VOLTAGE (VREF) - Power supplied by the ECA to some sensors that are regulated at a specific voltage.

STARTER RELAY:

RELAY - An electromagnetic switching device using low current to open or close a high-current circuit.
RELUCTANCE - The resistance of a material to the flow of magnetic lines of force.
REQUIRED VOLTAGE - Voltage necessary to overcome the resistance of the secondary circuit and establish a spark to the ground electrode of the spark plug.

RESERVE CAPACITY - The length of time that a fully charged battery at 80~F will remain functional when it is discharging at a rate of 25 amps. This rating is intended to tell the driver how long the car can be operated with headlights and certain other accessories on after an alternator failure.

RESIDUAL MAGNETISM - Slight magnetic properties retained by metal, such as a wiring coil in a generator, after it has passed through a magnetic field.

RESISTANCE - The opposition offered by a conductor to a flow of electricity; measured in ohms.

RESISTOR - A device installed in an electrical circuit which tends to prevent or reduce the flow of current.

RESUME - An operating mode of the speed control system which reactivates the system after it has been disabled (such as by stepping on the brake or clutch pedal) and returns it to the speed at which it was previously set. Shutting the vehicle off erases the resume memory.

RHEOSTAT - A device for regulating a current by means of a variable resistance.

ROTOR:

ROTOR - The rotating part of a distributor that transfers current from the coil cable to the spark plug cables.