Checking the generator for voltage drop
1. The check is performed on a warm engine.
2. Connect the tachometer, start the engine and turn on all powerful consumers (heater fan, high beam headlights, etc.).
3. Bring the speed to 2400 rpm and without changing the speed, do the following.
4. Check the voltage between (+) -battery pole and hairpin (not a nut!) terminal B+ of the generator, which should not be higher than 0.6 V. If the voltage is higher than 0.6 V, then touch the nut and the wire end on the generator. If the voltage drops below 0.6 V, then this indicates a bad contact in the connection. In this way, any section of the circuit can be checked if there is a suspicion of a connection failure.
5. Check the voltage between (-) - the battery pole and ground stud on the alternator housing, which should be no higher than 0.3 V. If the voltage is higher than 0.3 V, then touch the nut and the wire lug on the alternator. If the voltage drops below 0.3 V, then this indicates a bad connection in the connection.
Generator Output Voltage Check
To perform this test, you must have a VAT-40 car tester (or equivalent) complete with rheostat and current transformer.
1. Check battery charge and belt tension
2. Check contacts in all connections for voltage drop (see above).
3. Warm up the engine
4. Connect the VAT-40 tester in accordance with the instructions.
5. Start the engine and bring the speed to 3000 rpm (all consumers must be disabled). After turning on the fan, turn the engine to idle for 15 minutes.
6. Bring the speed to 2000 rpm. The voltage should not be higher than 15.1 V. Otherwise, check the charge current with a current transformer that covers the terminal B wire on the generator.
7. To do this, bring the speed to 2000 rpm. The voltage must be at least 13.5 V. Otherwise, replace the alternator.
8. Connect the load dummy of the tester and set the current so that the voltage drops to 12-13.5 V. If the charge current is less than 75 A, then check the voltage regulator and the generator in the generator full excitation mode. To do this, insert the probe from the tester kit into the hole in the rear cover of the generator and bring the engine speed to 2000 rpm. If the current is greater than 65 A (CR-V) or 75A (Odyssey) , then replace the voltage regulator, if less than the specified values, then replace the generator.