Session 4: Checking of Electrical Connections of Lighting System in a Vehicle
Module 5: Auto Electrical System
Textual Question-Answers
Check Your Progress
Fill in the blanks
1. Circuit testing is a ……………. approach to locating the cause ofa problem in a vehicle’s lighting system.
Ans: systematic
2. To effectively diagnose a circuit problem, it’s important tounderstand how the circuit should……………Ans: operate
3. Checking for ………………..connection before testing involvescleaning and tightening the ground.
Ans: poor
4. A short to ground can be located by using a self-powered testlamp or ……………with power disconnected from the circuit.
Ans: ohmmeter
5. When using a voltmeter to check for voltage, the reading shouldbe within ………………of battery voltage.
Ans: one volt
6. In an unfused circuit, if there is a short to ground, the conductormay ……………and possibly burn.
Ans: overheat
Multiple Choice Questions
1. What is the purpose of checking the lighting system in a vehicle?a) To save fuel
b) To reduce emissions
c) To ensure vehicle safety and compliance with laws
d) To increase engine performance
Ans: c) To ensure vehicle safety and compliance with laws
2. Which of the following is NOT a component of a lighting circuitin a vehicle?
a) Circuit protector
b) Engine block
c) Switch
d) Connector
Ans: b) Engine block
3. What is the potential danger if a lighting circuit in a vehicle is notoperating properly?
a) Increased fuel efficiency
b) Enhanced driving experience
c) Risk to driver and other people
d) Improved audio system performance
Ans: c) Risk to driver and other people
4. Which tool is used to check for voltage in a lighting circuit?a) Hammer
b) Screwdriver
c) Test lamp or voltmeter
d) Pliers
Ans: c) Test lamp or voltmeter
5. Why should a test lamp not be used in circuits containing solidstate components?
a) It can improve circuit performance
b) It may damage the circuit or components
c) It can increase circuit resistance
d) It may cause overheating of wires
Ans: b) It may damage the circuit or components
6. How can you locate a short to ground in a wiring circuit?a) By disconnecting the load and fuse, then wiggling the wiringb) By increasing the circuit voltage
c) By using a test lamp only
d) By disconnecting the battery
Ans: a) By disconnecting the load and fuse, then wiggling the wiringAnswer the following questions
1. Discuss the importance of checking the electrical connections ofthe lighting system in a vehicle.
Ans: Checking the electrical connections of the lighting system isimportant to ensure proper operation of vehicle lights. Loose, corroded, ordamaged connections can cause dim lights, flickering, or complete failure.
Proper connections ensure correct voltage supply, improve safety during night
driving, and help comply with traffic regulations. Regular inspection preventsaccidents and reduces electrical faults.
2. Write the general procedure of testing the automobile lightingcircuit for the following parameters.
a. Voltage
Ans: To test voltage, switch on the light circuit and set the multimeter tovoltage range. Connect the positive probe to the power side of the circuit andthe negative probe to ground. The voltage reading should be close to batteryvoltage.
b. Ground
Ans: To test ground, connect one probe of the multimeter to the groundpoint and the other to the battery negative terminal. A low resistance or zerovoltage drop indicates a good ground connection.
c. Shorting
Ans: To test for shorting, disconnect the power supply and load from thecircuit. Use an ohmmeter or test lamp to check for unwanted continuity between the conductor and ground.
d. Continuity
Ans: To test continuity, switch off the power and set the multimeter tocontinuity mode. Connect the probes across the circuit. A beep or lowresistance reading indicates continuity.
3. Draw a circuit diagram of the lighting system of any Indian car.
Ans: A typical lighting circuit diagram includes the battery, fuse, light
switch, dimmer switch, headlamp bulb, ground connection, and connectingwires arranged in series and parallel combinations.
4. Write about different faults of the lighting system of a car, theircauses and remedies.
Ans: Common faults in the lighting system include dim lights due to poorgrounding or low voltage, blown fuses caused by short circuits, flickeringlights due to loose connections, and non-functioning lights due to faulty bulbsor switches. Remedies include tightening connections, replacing blown fuses,
repairing wiring, and replacing defective components.
Activity
1. Make a list of the problems that can take place in four areas of alighting circuit.
Ans:
1. Name of the area: Power supply
Problems: Blown fuse or low battery voltage
2. Name of the area: Switch
Problems: Worn or faulty switch contacts
3. Name of the area: Wiring and connectors
Problems: Open circuit, short circuit, or loose connections
4. Name of the area: Ground
Problems: Poor or corroded ground connection
2. Prepare a poster showing a headlight circuit diagram and label
all the components.
Ans: The poster should show a headlight circuit diagram with labeledcomponents such as battery, fuse, headlight switch, relay, dimmer switch,
headlamp bulb, ground point, and connecting wires. Try youself
