Hi guys, my wife today was having some difficulties to start my civic to go to work.
The car has a new bosch battery that I fitted myself last May. Today was minus 2 degrees here where I live but for the last few days the temperature was a bit lower than that and the car was starting as usual.
I was commenting with one of my friends and he came up with one idea that I never heard about. He said to me to start the engine and disconnect the positive cable of the battery, if the engine is still running it is because the alternator is charging normally, if the engine dies it is because the alternator is going bad and I need a new alternator.
Has anyone heard anything similar or tried this?

 

Do not do that old test, it can generate a nasty power surge that will burn electronics out on a modern car. The proper way to check the alternator is to measure the voltage at the battery with the engine running but everything else switched off. It should be more than 13.8 volts.

A test you can do without a voltmeter (although if you want to work on your own electrical problems, it is inexcusable not to own one) is based on watching the output from the headlights (best done at night). Turn the headlights on with the engine running. Then turn the key off to stop the engine, the lights should dim slightly because the alternator stopped charging.

 

Thanks for the help