ABS sensor – Electrical part of the Anti-lock Braking System (ABS) to assist the driver control the braking system. The sensor detects wheel lock-up and prevents tires from locking and skidding, allowing the driver to maintain a controlled stop using electrical pulses to the braking system.
A/C belt – A belt used to spin the air conditioning (A/C) pump, shaped in a ‘V’ or serpentine configuration.
A/C compressor – A pump that utilizes compressed air and refrigerant to blow cold throughout the vehicle’s A/C system.
A/C compressor clutch – This part works in concert with a magnetic solenoid to operate the A/C compressor from the climate control panel inside the vehicle at the driver’s command.
A/C compressor seal kit – A kit consisting of the seals and O-rings that are required in order to reconstruct or repair the A/C compressor.
A/C hose – This can be any one of several hoses, made of metal or rubber, that are used to spread refrigerant through the A/C system.
A/C O-rings – These are rubber rings shaped like an ‘O’ that are positioned at all connections and joints within the A/C system in order to prevent refrigerant from leaking out.
A/C relay – The electrical component that acts as a relay between the electrical system of the vehicle and the AC compressor.
A/C switch – Any one of a number of switches that are used to control the functions of the A/C system.
A/C tensioner pulley – A circular shaped pulley mounted on the A/C compressor that is used to adjust the tension manually on the A/C belt.
Air cleaner mounts – This is a rubber part, normally containing a metal piece on either side, used to cushion the vibration of an engines’ air cleaner assembly.
Air filter – A filter, made of cardboard or a reusable and cleanable material, that filters debris out of the outside air that is being inducted into the engine.
Alternator – A component of the electrical system, this device is driven by a V-belt or serpentine belt and produces direct current (DC) electricity. The DC power is then routed into the vehicle’s charging system so as to keep the battery fully charged.
Alternator belt – A V-belt or serpentine belt used to drive the alternator.
Alternator tensioner pulley – Similar in design to an A/C tensioner pulley, this serves the same purpose and allows manual adjustments to the alternator belt’s tension.
Auxiliary fan – A separate fan that cools the A/C condenser.
Axle – This is part of the drive train system, connecting the transmission or trans-axle to the wheels, transferring the mechanical power of the engine to the wheels and enabling motion.
Axle nut – A nut, threaded on the inside, that is used to secure the outside end of the axle to the wheel.
Axle seal – This seal prevents the trans-axle (in a front wheel drive vehicle), or the differential (in a rear wheel drive vehicle) from leaking.
Ball joints – A component of the steering system, this part is made of a steel ball socket with threaded shaft that is attached to the steering knuckle at one end and the control arm at the other end. In this manner, the ball joints give a solid basis to the steering system.
Brake caliper – A mechanical component of the braking system, the caliper receives pressure from brake fluid, causing its hydraulic piston to push on the brake pad, which then makes contact with the brake rotor and slows/stops the vehicle.
Brake dust shields – A thin circular piece between the wheel and the braking system that prevents brake dust from escaping onto the wheels.
Brake hose – Disc brakes: this hose is the connection between the calipers and steel brake supply line. Drum brakes: this hose is the connection between the wheel cylinder and the steel brake supply line.
Brake lines – The ‘veins’ of the braking system, these small tubes carry brake fluid from the master cylinder inside the engine compartment to the various parts of the hydraulic system.
Brake pads – These pads press on the brake rotors after being pressed upon by the caliper pistons, enabling the vehicle to slow/stop.
Brake pad spring – This small spring acts as a mechanical cushion for the brake pads and helps to limit brake noise that are caused by shifting pads.
Brake pins – In a fixed caliper design, brake pins are inserted through the caliper to hold the brake pads in place.
Brake rotor – This large disc is connected to the wheel, and when squeezed by the brake pads, caused the vehicle to slow/stop.
Brake sensor – Due to the constant friction necessary for the brake pads and rotors to effectively slow/stop a vehicle, this electrical device senses when the brake pads are worn and alerts the driver through a light located inside the dashboard instrument cluster.
Brake shim – A thin metallic piece that is inserted between the brake calipers and brake pads in an effort to reduce noise.
Brake shoes – Used in vehicles with drum brakes, these act much the same as brake pads that squeeze a rotor from the outside. These semi-circular shoes are mounted on the inside of a brake drum, and when pressure is applied to the brake pedal inside the car, the shoes press outward on the inside of the drum in order to slow/stop the vehicle.
Brake shoe springs – A small metallic spring mounted on the inside of a brake drum, used to secure the brake shoes to each other and to the brake show backing plate.
Breather hose – Any one of a various number of rubber hoses that are used to distribute air throughout the engine.
Bypass hose – Part of the engine cooling system, this rubber hose passes engine coolant from the thermostat housing to the water pump.
Cabin filter – A barrier between outside air and the passenger compartment, this filters the air coming into a vehicle.
Cam gear – This mechanical gear is used to drives the engine’s camshaft.
Camshaft position sensor – This electrical devices sends a signal to the on-board computer, constantly reporting the camshaft positioning.
Catalytic Converter – A section of the exhaust system that oxides exhaust gases from the engine into water and carbon dioxide.
Climate control panel – A panel inside the passenger compartment that allows the driver to control the internal temperature of the vehicle through the use of a fan, heater, and air conditioner. This panel may consist of any variety of knobs, buttons, switches or dials.
Climate relay – A part of the electrical system that relays signals to and from the climate control system.
Clutch cable – A flexible metal cable that disengages the transmission from the engine when the clutch pedal inside a vehicle is pressed.
Clutch disc – Located inside the transmission, this disc has carbon fibers on either side and acts to make the transition of power between engine and transmission smooth.
Clutch kit – This kit normally contains everything a person would need to replace the clutch in vehicle (clutch disc, pressure plate, pilot bearing, release bearing, and often the pilot shaft tool).
Clutch master cylinder – In a vehicle with a hydraulic clutch, this replaces the manual clutch cable. When the clutch pedal is pressed, pressure is sent hydraulically to the clutch slave cylinder, which disengages the clutch.
Clutch slave cylinder – In a hydraulic clutch system, this part is between the clutch master cylinder and clutch itself. When hydraulic fluid is applied to the this cylinder, a rod extends and presses on the clutch fork, thereby activating the clutch.
Compressor – Part of the refrigeration system, this passes refrigerant vapor from an evaporator to a condenser.
Computer – In newer vehicles, all vehicle systems are controlled and/or monitored by the on-board computer, which will notify the driver through the dashboard instrument panel of any problems.
Condenser – P art of the refrigeration system, vaporized A/C refrigerant circulates through the condenser passes through fins, which cool the refrigerant back into a liquid.
Condenser motor – Used to assist the condenser in cooling A/C refrigerant once the system rises above a certain pressure or temperature.
Control arm – This is a suspension system component which connects the vehicle frame to the steering knuckle or front axle carrier in the front end of the vehicle. In the rear of the vehicle, the control arms connect the vehicle frame to the rear axle carrier.
Control arm bushing – A bushing, fitted in either end on the control arm to assist with cushioning and preventing wear.
Crankshaft gear – The gear which sits on the front of the crankshaft and is used to drive all other timing and auxiliary gears.
Crankshaft position sensor – Similar in function to the camshaft position sensor, this electrical device sends the positioning of the vehicle’s crankshaft to the on-board computer.
Crankshaft seal – Positioned at the front and rear ends of the crankshaft, these round seals prevent leaking.
CV Boot – The constant velocity (CV) boot is a rubber covering which contains grease to lubricate the CV joint and also keeps dirt and debris out of the CV joint.
CV Joint – There are two rounded CV joints on a vehicle, the front inner and front outer. The front inner connects the axle from the transmission/trans-axle output flange and delivers power from the flange. The front outer is similar to the inner, but delivers power to the flange, instead of from it, causing the wheels to drive the vehicle.
Cylinder head – A detachable iron or aluminum part which sits directly above the engine cylinders. The head contains part of the combustion chamber, and houses the intake/exhaust valves, valve guides and springs, and spark plugs. On an overhead camshaft (OHC) engine, the head contains the camshaft as well. It is within the cylinder heads that internal combustion occurs, allowing the vehicle to produce horsepower and momentum.
Differential seal – This seal is found on the differential (normally on the side) and prevents oil from leaking from the differential.
Distributor assembly – Part of the ignition system, this is a combination electrical and mechanical device which receives a spark from the ignition coil and sends that spark in correct firing sequence to the engine’s spark plugs, with are located inside the cylinder heads.
Distributor cap – This is a spherical plastic cover that sits over the distributor to protect the inner assembly. The spark plug wires coming from the spark plugs are plugged into the top of the cap.
Distributor rotor – A plastic device, just below the distributor cap, which receives spark from the ignition coil and spins to transmits that spark to the spark plugs through the spark plug wires.
Door check (door brake) – A limiting strap which only allows the doors to open a specific distance, preventing damage to the door and stopping it from hitting the fender.
Door handle – The mechanism on the exterior of the doors used to gain entry into the vehicle. Also, the handle located on the inside of the door used to open the door and exit the vehicle.
Door seal – A gasket, traversing the border of the door which keeps out water, debris and noise when the vehicle doors are closed.
Drag link (center link) – On conventional steering systems, this connects the driver and passenger side outer tie rod assemblies.
Drive belt – A belt, serpentine or V shaped, which is used to connect and drive the majority of, if not all pulleys in the drive belt system.
Driveshaft center support – This piece, constructed of metal and rubber, connects the front and rear portions of the driveshaft and provides stability and smooth driving.
Driveshaft drive disc – A round disc, made of rubber, which connects the transmission output flange to the front portion of the driveshaft, assisting in providing a smooth overall power transfer.
EGR valve – The exhaust gas recirculation (EGR) valve is a part in the engine that recycles fuel not consumed in the combustion process back into the intake system.
EGR valve gasket – The rubber seal found between the EGR valve and intake.
Emblems – Insignias on the vehicle which denote any manner of make, model, special features, etc.
Emergency brake shoes – Similar to regular brake shoes, these press outward against the inside of the brake rotor, but only when the emergency brake in engaged.
Evaporator – Part of the cooling system, this part receives A/C refrigerant and through warm interior air passing over the fins, evaporating and changing the refrigerant from a liquid to a vapor.
Exhaust gasket – Found withing the exhaust system, these gaskets seal areas where metal contacts metal and prevents leaks and excess noise.
Exhaust manifold gasket – This part is found between the cylinder head and exhaust manifold, and serves to prevent leaks.
Exhaust valve – A metal disc with a stem protruding several inches, this is a component of the combustion system. These valves, when opened, allow exhaust gases from the combustion process to escape and are then routed to the exhaust system.
Expansion valve – A portion of the cooling system, this valve is metered and allows liquid refrigerant to change to vapor.
Fan belt - A V-belt which is driven by the crankshaft pulley, this item turns the radiator fan and water pump, resulting in the engines ability to cool itself.
Fan switch – An electrical device which turns on the cooling fan automatically once the internal temperature of the engine reaches a predesignated point.
Flasher relay – An electrical which powers emergency hazard lights from the battery.
Fog light assembly – This assembly consists of fog light and housing assembly.
Fog light lens - A plastic or glass lens which covers and protects the fog light bulb.
Fuel injector – Part of the combustion system, these small injectors spray tiny amount of fuel into the combustion chamber.
Fuel injector O-rings – Rubber gaskets used to seal the fuel injectors and prevent leakage.
Gas cap – A cap constructed of metal or plastic that seals the gas tank fill port when not in use.
Gas cap gasket – This gasket seals the area between the gas cap and gas tank fill port, preventing air from entering when vehicle is in operation.
Glow plug – Found in diesel engines, this is an electric heating element that enables diesel engines to start when the engine is cold.
Glow plug fuse – A fuse placed in the electrical path of the glow plug system,this is used to protect the electrical system in the event to much current is drawn to the glow plugs.
Glow plug relay – This electrical device enables power to flow to the glow plugs from the electrical system.
Grille – Located on the exterior of the vehicle in the front between the hood and the bumper. Cosmetic in nature, this is a decorative part.
Grille moulding – A strip of metal or plastic that adds a decorative element to a vehicle’s grille.
Head gasket – The rubber or composite gasket that seals the area between the cylinder heads and the engine block to prevent the mixing of coolant and oil.
Head gasket set – This set contains all the seals that need to be replaced in the event a cylinder is removed or replaced. The set usually consists of all the various gaskets, to include valve cover gaskets.
Headlight assembly – This assembly consists of the headlight lens/housing and the mounting structure.
Headlight lens – This is a plastic or glass covering designed to protect the headlight bulb.
Heater control valve – This valve is controlled by the operator of the vehicle as the climate control system is adjusted. Depending on the input required by the driver, this valve will be open, closed or partially open, affecting the amount of coolant that enters the heater core.
Heater hose – One of two rubber hoses which either provide coolant to the heater core or a return of coolant to the engine.
Heater motor – This is controlled by the driver when adjusting the interior temperature of the vehicle. Depending on the input required by the driver, the motor will blow either heat or A/C air.
Hood pull – A cable linking the hood release handle to the hood latch.
Hood release handle - A handle linked to the hood release by the hood pull, found inside a vehicle and is used to release the hood latch.
Hub – This steel disc attached to the end of the axle containing the wheel bearing and where the wheel is attached to.
Hub bolts – The straight bolts that hold a rotor to the hub.
Idler arm – A component of the steering system, the idler arm assists stabilization by enabling the tie rod assembles and center link to pivot left and right.
Idler arm bushing – This piece fits inside the idler arm and cushions movement.
Idler pulley – This pulley contains a bearing and is utilized to assist a fan, drive or timing belt.
Igniter – An electro-mechanical device which uses electricity to power the ignition coil.
Ignition coil – This devices uses a magnetic coil and electricity to produce spark to start an engine.
Ignition control unit - An automated electronic part modulates an electrical signal which then transmits power to the ignition system.
Ignition rotor – See distributor rotor.
Ignition wires – Cables linking the distributor cap to the spark plugs and transmit a spark from the ignition coil to the spark plugs.
Intake hose – This part takes outside air and delivers it to the engine intake.
Intake manifold gasket – This part seals the area between the cylinder head and intake manifold, preventing leakage.
Intake valve – Similar in design to an exhaust valve, these allow air to enter the combustion chamber and mix with the fuel from the injectors, a precursor to combustion.
Intermediate gear – This refers to any gear inside a transmission which is between the lowest and highest gears. Also refers to a gear used to indirectly propel a device, I.e. an oil pump.
Main bearings – Half circle metallic parts that consist of two pieces to make a full circle, these are the bearing which the crankshaft rotates upon.
Mass air sensor – Typically found in more modern vehicles, this is a component of the fuel injection system. This sensor measures and meters the outside air that enters the engine.
Mirror – Mounted either on the exterior or the driver and passenger doors and in the top middle of the inside of the windshield, these allow the driver to look behind and to the sides enhancing field of vision.
Motor mount – These rubber parts cushion and absorb shock between the engine and the vehicle frame, reducing vibration and noise.
Muffler – A component of the exhaust system, this piece dampens or “muffles” the exhaust noise of a vehicle.
Oil cap – Similar in construction and function to a gas cap, this part is located at the top of a valve cover and must be removed to add oil to the engine.
Oil cap gasket – This gasket seals the area between the oil cap and valve cover, preventing oil from escaping the engine and keeping debris and dirt out o the engine.
Oil dipstick – A thin, marked metal piece which terminates in an engine’s oil pan, this part can be easily withdrawn in order to measure the amount of oil inside the engine.
Oil level sensor – This electrical device monitors the oil level of the engine and reports the most current status to the driver.
Oil pan – This part is located at the very bottom of the engine and holds the engine oil when it is not in use lubrication the engine.
Oil pan drain plug – This small, threaded plug is located at the lowest point of the oil pan, the removal of which allows the engine oil to drain.
Oil pan drain plug washer – This small disc, usually either metal or rubber, seals the area between the oil pan and drain plug, preventing oil leakage.
Oil pan gasket – This piece, usually rubber, seals the area between the top of the oil pan and the bottom of the engine block.
Oil pressure switch – This electrical device measures the oil pressure inside an engine, and will report to the driver via the dashboard instrument panel if something is amiss, usually in the form of a light or gauge.
Oil pump – This part enables oil to circulate throughout the engine, lubricating vital parts of the engine and preventing break down.
Parking pawl – This small part is found in automatic transmissions, and it prevents the vehicle from rolling by locking up the transmission when the shift lever is placed in ‘Park’.
Pilot bearing – Found in vehicles with manual transmissions, this bearing is found at the end of the crankshaft inside the flywheel, and helps guide the end of the main-shaft.
Piston – This metal cylindrical object is propelled upward in the cylinder by the crankshaft, and forced back downward by the combustion that takes place above it when it is all the way up. This rapid back and forth provides power to the engine.
Plenum gasket – These gaskets, separated into an upper and lower, seal the area between the plenum chamber and the intake manifold.
Power steering belt - A serpentine or V-belt, usually between the power steering pump and crank or main pulley, used to drive the power steering pump.
Power steering filter – This part filters debris and foreign substances out of power steering fluid inside the power steering pump.
Power steering pump – This hydraulic pump forces power steering fluid throughout the steering system, simultaneously protecting the internal parts from damage and making the steering easier to operate for the driver.
Power steering pump repair kit – This kit contains all necessary replaceable pieces to rebuild or replace a power steering pump.
Pressure plate – Found in vehicles with manual transmissions, this is a round metallic part containing springs that works to disengage the transmission from the engine when the clutch pedal is pressed down. In reverse, the pressure plate allows the transmission to re-engage when the pressure on the clutch pedal is removed.
Radiator fan motor – This part engages the cooling fan, providing additional cooling capability to the radiator once the operating temperature of the engine reaches a certain level.
Radiator hose – Similar in function to a heater hose, there are two of these that connect the engine and radiator. The first hose supplies coolant to the engine, where the heat is transferred to the liquid. Then the heated liquid will pass through the second hose back to the radiator, where it will cool before being cycled back into the engine.
Radiator mounts – These parts act similar to motor mounts, although these only cushion the radiator.
Rear glass seal – The rubber weatherstripping that seals between the vehicle body and rear window, keeping out air, water, and debris.
Receiver drier – A part of the A/C system, this canister contains a substance that absorbs moisture from A/C refrigerant.
Reference sensor – This electrical device send information to the computer relative to the cam or crankshaft positioning to ensure the engine knows when to fire the ignition coil.
Relay – An electrically operated switch which allows a smaller amount of voltage to control a larger amount of voltage.
Release bearing – Found in vehicles with manual transmissions, this assists the pressure plate in disengaging and re-engaging the transmission.
Rocker arm – This is a metal lever, found underneath the valve cover over the cylinders which pivots back and forth to either open/close the intake and exhaust valves.
Rod bearings – These are half circle metallic pieces that combine to create a full circle. These bearings fit between the connecting rod and rod journal on the crankshaft, enabling the pistons to be attached to the crankshaft.
Serpentine belt – A continuous loop of rubber that is used to drive most of the pulleys that operate devices inside the engine.
Shifter bushing – This small part is normally constructed of rubber and insulates between the transmission and transmission linkage.
Shifter knob – This part is found on the end of the shift lever and makes it easier for the driver to change gears.
Shock absorbers – Cylindrical parts that attach between the vehicle’s suspension system and the frame of the vehicle, these collapse in on themselves in order to lessen the severity of bumps in the road and to protect the components of the suspension system.
Spark plug – A component of the ignition system, this device is threaded into the cylinder head above the combustion chamber at the top of the pistons. Once spark is transmitted via the ignition coil, these plugs provide that spark at the right time to create combustion inside the chamber.
Spark plug connector – Found on either end of spark plug wires, this is a metal boot encased in rubber that delivers the spark from the ignition coil via the distributor to the spark plug.
Speedometer cable – This part connects between the transmission and the speedometer located on the dashboard instrument panel, enabling the driver to be aware of and measure the vehicles speed.
Spindle – Part of the steering system, this attaches to the control arms and carries the hub for the wheel to mount on.
Spindle nut – A nut, threaded on the inside, that secures a rotor to a spindle.
Starter – The motor that is engaged by the ignition system to spin the flywheel and activate the ignition and fuels systems enabling the engine to start.
Steering box – The central point of the steering system, this metal box connects the steering components through use of a pitman arm, enabling the driver to change course using the steering wheel.
Steering box repair kit – This kit has all necessary replaceable items to repair or replace a steering box.
Steering knuckle - A component of the steering system, the knuckle mounts between the ball joints and enable the wheel to pivot.
Steering rack – In rack and pinion steering, the rack is a set of gears that converts rotational energy into linear movement, enabling the side to side steering of a vehicle.
Sunroof seal – This piece of weatherstripping seals the area between the body of the vehicle and sunroof, preventing air and water from entering the vehicle.
Sway bar bushings - These secure the sway bar to the vehicle’s frame.
Sway bar link – These attach the sway bar to the frame through a swivel socket at either end of the bar.
Tail light assembly – Similar to a headlight assembly, this consists of a tail light lens and housing, with accompanying mounting structure.
Tail light lens - A plastic or glass covering designed to protect the tail light bulb.
Tensioner assembly - A mechanical device which maintains even tension on a belt, enabling it to contact all pulleys appropriately.
Thermostat - A mechanical piece which opens as the engine temperature warms and allows coolant to pass freely, and closes when the temperature cools sufficiently.
Thermostat housing gasket – A gasket that seals the area between the engine block and thermostat housing to prevent coolant leakage.
Thermostat O-ring – A rubber seal in the shape of an ‘O’ which seals the thermostat cover and prevents leakage.
Thrust bearings – These are shaped and sized specifically to allow for the proper clearance for movement in the crankshaft.
Tie rod end – A component of the steering system that connects the vehicle frame to the steering system.
Timing chain – Also known as a timing belt or cam belt, this controls the timing of the engine’s valves opening and closing.
Timing chain kit - This kit provides all necessary replaceable pieces for the timing chain.
Transmission drain plug – Similar in function and design to the oil drain plug, this is located on the bottom of the transmission pan and enables the draining of transmission fluid.
Transmission drain plug washer – This washer is used to seal the area between the transmission and the transmission drain plug.
Transmission filter - This filters debris and foreign substances from transmission fluid, preventing undue wear on the transmission.
Transmission pan gasket - A gasket which seals the area between the transmission pan and the transmission.
Transmission mount - Similar in functionality to a motor mount, this rubber and steel part cushions and helps control vibration on the transmission.
Transmission seal – This seals the front or rear of a transmission, keeping the fluid inside.
Trunk seal- A gasket that seals the area between the trunk and trunk lid, preventing water or wind noise from entering the trunk.
Turbo – Also known as a turbocharger, this device increases horsepower by increasing the density of the air entering through the intake system.
Turn signal lens - A cover, usually plastic, which protects the turn signal bulb.
Turn signal light assembly – This part, located at the four exterior corners of a car, will blink and indicate the direction the driver wishes to turn.
U joint – A universal joint connects two moving shafts that are not lined up. This part of the drivetrain allows the drive or axle shafts to operate at differing angles and still transmit power to the wheels.
Vacuum pump - A device that uses suction to power additional devices such as a vacuum booster for a hydraulic braking system.
Vacuum pump repair kit - A kit which contains the necessary replaceable parts to repair or replace a vacuum pump.
Valve cover – This covers the valve area on top of the cylinder head, protecting the moving parts within and keeping oil inside.
Valve cover gasket - A gasket that seals the area between the valve cover and the cylinder head, preventing any oil leakage.
Valve seals – These seals prevent oil from the valve area leaking down inside the combustion chamber when they open.
Warm-up regulator – This device, using engine temperature as interpreted by the computer, controls the fuel pressure in an engine.
Water pump – This pump is part of the drive belt system and circulates coolant inside the engine to regulate temperature and prevent overheating.
Wheel bearing - A greased ball bearing that allows the wheel to spin without producing friction.
Wheel bolts – These threaded bolts secure a wheel to the wheel hub.
Wheel cylinders – These cylinders are utilized alongside brake shoes in a hydraulic braking system.
Wheel seal – This prevents the grease surrounding the wheel bearing from coming out and also keeps dirt and debris out of the bearing.
Window motor - This electric device, found in most newer vehicles, allows the windows in the passenger compartments to be raised and lowered with a button or switch.
Window regulator – When no window motor is present, the regulator allows use of a mechanical handle to manual raise and lower the window.
Windshield seal – Similar in construction and function to the rear window seal, this seals the area between the body of the vehicle and the windshield, forming and air and water tight bond.
Wiper arm – This part is attached at one end to the wiper motor and uses spring pressure to hold a rubber wiper blade onto the window.
Wiper blade – An insert between the wiper arm and the windshield, this soft rubber strip contains a metal backing and is used to wipe the windshield clean.
Wiper blade refills – Also referred to as inserts, this is the replaceable rubber portion of the wiper blade.
Wiper motor – This electric device is powered by the vehicle’s electrical system in order to operate the wiper arms.
Wiper relay – The electrical relay which transmits power to the wiper motor.