03DelcoRemy Diagnostic Manual130004222020

delcoremy.com Page 1 1-1. INTRODUCTION 1-2. PURPOSE. This manual provides diagnostic procedures that can be used for troubleshooting a heavy duty electrical system, including the starting and charging systems. Some procedures also may be used for preventative maintenance checks. These procedures are applicable to systems using heavy duty starters such as: Delco Remy 28MT™, 29MT TM , 31MT™, 35MT TM , 37MT TM , 38MT TM , 39MT TM , 41MT TM , 42MT TM , 50MT TM or a similar starter with adequate battery power for the engine/starter application used. 1-3. DEFINITION OF DIAGNOSIS. Diagnosis is the three-part process that begins when a problem is perceived and ends when the equipment is confirmed as serviceable. Three questions must be answered to assure completion: 1. What are the symptoms? This is what has been observed (seen, heard, felt or smelled), indicating a problem. 2. What caused the symptoms? Diagnostic procedures are used to identify the root cause of the problem. 3. How do we fix it? Usually this involves the adjustment, repair or replacement of some part or parts. 1-4. This manual defines the procedures to determine the cause of the symptoms. Actual adjustment, repair and replacement procedures are provided in unit-specific service bulletins and manuals. 1-5. For educational purposes, study of this entire manual is recommended. For diagnostic purposes, the flow charts in Section II will reference appropriate procedures for specific symptoms. 1-6. EQUIPMENT REQUIRED. To perform the tests specified in this manual, the following equipment is required: 1. A variable carbon pile load tester with more than 500 amps capacity with ammeter (and voltmeter). 2. A separate DC voltmeter, digital preferred, capable of reading 0.01 volt increments. 3. An inductive (clamp-on) ammeter for safe and accurate current measurements. 4. A hand held or bench top type tester. 1-7. DESCRIPTION 1-8. SYSTEM. The heavy duty electrical system is comprised of the starting and charging systems. These systems are, in turn, comprised of batteries, the starter, the alternator, and the interconnecting wiring and electrical and mechanical switches. For maximum operating efficiency, all parts of the system must be functioning properly. S E C T I O N 1 Introduction and Description FIGURE 1-1. Heavy Duty Electrical System 1. Battery 2. Starter 3. Alternator 4. Magnetic Switch 5. Push Button Switch 6. Key Switch