Is it safe to test alternator by removing battery cable?
Technically yes, but that test can also wind up destroying all the electronics in your car; PCM, TCM, electronic power steering, radio, etc. Testing alternator by removing battery cable was a valid test back in the day before computers. But it’s no longer a safe test to perform on a modern vehicle.
Do you have to test battery cable before replacing it?
It is usually a good idea to test, and if necessary replace, less expensive items like the battery cable before replacing a high-priced starter or battery. Have someone sit in the vehicle to be ready to crank the engine. Set the multimeter to measure voltage.
Where does the positive battery cable go in a car?
If your battery is in the trunk, the positive cable will attach to another connector near the body of the car. Simply disconnect it from there. Remove the battery. Some cars will not require the removal of the battery while replacing battery cables, but even if it is not necessary, it may make the process easier.
Do you need to change the battery cable in your car?
Replacing your car’s battery cables is an inexpensive first step to troubleshooting an electrical issue with your car, and may even solve your problems. Put on safety glasses and gloves.
When to know if your alternator or battery is bad?
If you check hours or days after the fact, then you won’t be able to smell anything anymore. Before you go out and order a new battery or alternator, test some of these different systems. If your alternator, coil, battery, or starter is bad, the car probably won’t start, and it definitely won’t be drivable.
What to do if your car battery is dead?
If the battery is dead check the headlight control switch. If the switch is in the on position turn the switch off and jump start or charge the battery. The battery should re-gain its state of charge after about 15 minutes of driving and your problem will solved. If headlight switch is off proceed to next step.
What happens when the alternator of a car is dead?
The alternator and the car’s battery work hand in hand. A good battery should give you service for the next five years before its lifespan ends. If your battery is dead, then it will not give power to the car’s alternator. The alternator normally lasts longer than the battery.
Can a Saab 92 start with a bad alternator?
Dual ignition coils (the blue cylinders at the top of the picture) on a Saab 92. Before you go out and order a new battery or alternator, test some of these different systems. If your alternator, coil, battery, or starter is bad, the car probably won’t start, and it definitely won’t be drivable.
Technically yes, but that test can also wind up destroying all the electronics in your car; PCM, TCM, electronic power steering, radio, etc. Testing alternator by removing battery cable was a valid test back in the day before computers. But it’s no longer a safe test to perform on a modern vehicle.
How do you connect battery cable to alternator?
Connect B+ battery cable to alternator. Turn on battery switch. Install a jumper from pin F in harness plug to B+ terminal on alternator. Note: the alternator charge wire routes direct to the battery and not through any switch connection, the alternator will not operate correctly if not connected direct to battery or directly through the ammeter.
What happens when you disconnect the battery from the alternator?
But it’s no longer a safe test to perform on a modern vehicle. The instant you disconnect the battery cables to test the alternator, the alternator goes into “full field” mode where it can generate a voltage spike as high as 150 volts! Yes, you read that correctly. That’s because the battery acts as a capacitor/shock absorber in the system.
What should I do if my alternator is not working?
The solution is to check your car’s manual for the particular fuse that controls the alternator and replace it. In some cars, you might also find another small fuse to the alternator’s control—usually a 15A to 20A fuse. An alternator does usually has 3 or 4 wires to it to function properly.