Checking and replacing the alternator on a Mazda 3 car
Vehicle test:
Check the voltage at the generator terminals
Make sure the battery is fully charged.
Check that the deflection and tension of the alternator belt are within specifications.
Turn off all electrical consumers.
Turn the ignition switch to the (START) position and check that the generator rotates evenly and does not make noise while the engine is running.
Measure the voltage between the terminals of the generator (see Fig. 1) at idle (at 20 ° C) according to the table
Checking the current strength at the generator outputs
Make sure the battery is fully charged.
Check that the deflection and tension of the alternator belt are within specifications.
Disconnect the cable from the negative battery terminal.
Place an ammeter between pin B and terminal.
Connect the cable to the negative battery terminal.
Turn off all electrical consumers.
Start the engine and set the engine speed to 2000-2500 min-1, measure the current at the generator output.
Measurements are made on a "hot" engine at an air temperature of 20 ° C and a voltage at the terminals of 13.5 V.
Current:
- at 1000 min–1 – 0–75 A;
- at 2000 min–1 – 0–98 A.
Turn on the following electrical consumers one by one:
- - headlights;
- – heater fan motor;
- - rear window heater.
Make sure that the current at terminal B of the generator gradually increases. If the current does not increase, repair or replace the alternator.
Checking the voltage at the generator outputs
|
Output |
Ignition switch in the "ON" position |
Voltage (20°С), In |
|---|---|---|
|
B |
B+ |
13-15 |
|
P |
~1B |
~3-8 |
|
D |
~0B |
* |
- Turn on the following consumers of electricity one after the other:
- headlights; - – heater fan motor;
- - rear window heater.
Removing and installing the generator
When the battery is connected, a breakdown may occur between the car body and terminal (B).
This may result in injury, fire, or damage to the vehicle's electronic components. Always disconnect the battery before removing the alternator.
Remove the battery cover. Disconnect the negative cable from the battery.
Remove the bottom cover together with the mudguard.
Remove the drive belt.
Fix the expansion tank of the cooling system so that it does not interfere with work.
Fix the power steering reservoir so that it does not interfere with operation.
Remove in the order shown in Figure 2.
Install in the reverse order of removal.
Remove bolt A with the alternator, as the months it is not enough to remove it (see Fig. 2).
