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Q: new alternator and battery. Car wont start, any pointers?

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So i've recently bought a new alternator and a new battery for my car but the red battery light still lights up. And now my car wont start. Can you help me?
My car has an automatic transmission.

Hello. This may be related to either a bad ground connection from the battery or potentially a bad voltage regulator. The other end of the black battery ground cable should be connected to the chassis of the car firmly. If this is not the case, this may potentially cause this problem. I would also recommend having the voltage regulator tested to see if it is working properly as well. If this is bad, it will also cause the light to come on as it will not charge the battery properly.

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