Automotive Service Technology Section C/Automotive Special Problems
Course HS Title:
Automobile Service Technology/Special Problems
KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No.
KCTCS Course Title
This lesson will instruct the student on how to identify abnormal operating noises in the A/C system, determine necessary action. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in an Automotive Repair Facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to an automobile accident or create customer satisfaction issues.
Identify abnormal operating noises in the A/C system; determine necessary action.
Given the proper tools and instruction, the student will be able to identify abnormal operating noises in the A/C system; determine necessary action, and pass a written test covering the task with 100% accuracy.
Tell students that before deciding the Air Conditioning System is the source of a noise, be sure and check the engine condition. Let them know that loose engine or exhaust system parts, loose belts, and even vacuum leaks can sound like a noisy compressor. Remind them to check all belt driven accessories, especially the water pump and air pump, if one is used. In addition to checking the accessories themselves, let them know too check for loose mounting bolts.
Instruct students that to diagnose a malfunctioning A/C system by sound, listen for these types of noises, and the likely causes of the noise.
* If they hear a grinding noise or roughness when the compressor clutch is engaged, check for a defective clutch bearing. * If they hear a heavy knocking sound at the compressor, it is likely internal damage. A clicking at the compressor would signify internal wear. * If students hear a squeal, rubbing noise, accompanied by blower motor vibration, often increasing with fan speed, tell them to check for defective bushings at the blower motor armature shaft.
* If they hear a squeal upon compressor engagement, have them check for a defective drive belt. Also, if they hear a high pitched squeal only when compressor engaged, tell them to also check for a compressor that’s seized or clutch seized. * If they hear thumps, whines, and bangs in the A/C system, tell them to check for system blockage or incorrect system pressures. * If they hear a honking noise, tell students to check for low refrigerant level. * If students hear a compressor that makes a chattering noise, have them check for a clutch plate that might be damaged or loose
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Evaluation and feedback Prior to Testing or Lab Work
Objective 1. / Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist will be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.
STUDENT ASSESSMENT: (Assess student progress with performance criteria.)
Objective 1 / Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)