Honda 31100-P12-A02 Alternator Assembly (Cjp76) (Denso)

Several precautions must be observed with alternator equipped vehicles to avoid damage to the unit. Always observe proper polarity of the battery connections and use extreme care when jump starting the car, as reversing the battery connections can cause the battery to explode or damage the one-way rectifiers. Remove the battery or, at least, disconnect the cables while charging to prevent alternator damage. Match and consider the polarity of the battery, alternator, and regulator before making any electrical connections within the system. Disconnect the battery ground terminal while repairing or replacing any electrical components. Never use a fast battery charger to jump start a vehicle with a dead battery, attempt to polarize an alternator, or use test lights of more than 12 volts when checking diode continuity. Avoid grounding or shorting out the alternator or regulator terminals, and do not separate the alternator on an open circuit; ensure all connections within the circuit are clean and tight. Refrain from using arc welding equipment on the car with the battery cable, PCM, or alternator connected, and do not operate the alternator with any of its or the battery's lead wires disconnected. Additionally, avoid subjecting the alternator to excessive heat or dampness, such as steam cleaning the engine. When utilizing a booster battery as a starting aid, always connect the positive to positive terminals and the negative terminal from the booster battery to a good engine ground on the vehicle being started.

During the test procedure the technician measures the decline in voltage between the alternator output wire that runs from the alternator terminal through the battery positive terminal and from the alternator ground terminal. A 0-18 volt DC scale voltmeter is needed for this test while test points become accessible through air cleaner housing removal or by lifting the vehicle. The testing process requires a fully charged battery with good condition while checking cables followed by engine start and warming up before engine shutdown. Start by installing the engine tachometer then activate the parking brake followed by engine start. Complete the process by activating HIGH blower speed and turning on both high beam lamps and interior illumination. To test the ground circuitry connect the negative voltmeter lead to the positive battery terminal along with the positive lead to B+ output terminal stud on the alternator while observing a voltage below 0.6 volts at 2,400 rpm engine speed. During the positive circuitry test connect the positive voltmeter lead to the negative battery terminal while the negative lead touches the ground terminal stud on the alternator. Avoid exceeding 0.3 volts. The test requires measurement of voltage between this alternator case and the engine. The output voltage test requires a well-conditioned battery as well as voltage drop verification and alternator drive belt tension inspection. Utilize the VAT-40 or equivalent tester to begin the engine at 3,000 rpm with all accessories shut off. Let the radiator cooling fan activate before allowing the engine to idle for 15 seconds. Use an engine speed of 2,000 rpm to check the voltage which needs replacement if it falls below 15.1 volts. The alternator requires replacement when the tested voltage exceeds the specified level. To start this test begin by letting the engine idle while all electrical features stay off and switch the VAT-40 to its charging mode to clear the ammeter display before securing the inductive pick-up unit on B terminal wiring of the alternator. To diagnose the alternator for failure run the engine at 2,000 rpm while measuring voltage; the replacement is necessary when the reading shows less than 13.5 volts. The charging system can be confirmed good if the alternator produces 75 amps or more when the voltage reduces between 12-13.5 volts. Probings require the radio security code before disconnecting both battery cables and removing the power steering pump and alternator's wiring and through bolt alongside the adjustment locknut and then removing the belt and finally the unit itself. The installer needs to follow torque standards for bolts and control the tension of the alternator belt throughout the installation. Specific engine types require the same alternator detaching and installing sequence yet require recording radio security codes and adjusting belt tension after completion.