Should you disconnect battery before pulling fuse?
It’s always best practice to disconnect a car’s battery before working on any electrical issue. Typically, you will only disconnect the negative cable that goes to ground (i.e. the car’s chassis).
What happens when you disconnect the battery from the alternator?
If your car keeps running upon unplugging the battery, it means the alternator is in good condition. The problem might lie in some other part of your vehicle. But if the car stops running, then the alternator configuration is not okay. A faulty alternator won’t be able to power the engine.
Why does my alternator not work when I start the car?
When you start the car using the battery, the alternator provides its power to keep the light on constantly. If the light glows properly, the alternator is working fine. But if the headlight is dim or keeps flickering, your alternator is struggling to power up the battery. The performance of the battery also is a crucial sign of a bad alternator.
What happens if I unhook the battery while the car is running?
Here’s the rub: the alternator’s regulator can only react so fast to a massive step change in load, such as when you unhook the battery while the car is running. (Especially if it’s a flat battery — if you are going to unhook the battery on a running car, make sure it’s fully charged first!)
When do I Disconnect the battery to stay?
Disconnect the battery whenever working on anything which is voltage sensitive, such as the Engine Control Unit (ECU – vehicle’s computer). This especially applies when working on the airbag system (SRS), though other precautions need to be taken there as well.
If you disconnect the battery, there will be a spike in the voltage from the alternator which will then send more that 14 volts to all the electronics in the car. This may damage these electronic components. Even in the old days before electronics, when cars had a generator,…
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.
What should I do if my alternator is not working?
Check if it’s properly supported by the hook rod or not. Start the engine. If your car is already having difficulties in starting the car it may take time to start it. If it starts, keep the engine running. Go back to the battery. Check if there is some dirt or corrosion around the battery’s terminal. Remove it if present.
Here’s the rub: the alternator’s regulator can only react so fast to a massive step change in load, such as when you unhook the battery while the car is running. (Especially if it’s a flat battery — if you are going to unhook the battery on a running car, make sure it’s fully charged first!)