I bought a new starter but when installed it ,it won't start
My car has an automatic transmission.
This may be a question of a weak battery or potentially a failing starter relay. If there is a fast ticking sound when turning the key, it is likely that your problem may be a battery that is simply too weak to turn the engine over. If there is no sound at all, it may possibly be a faulty starter relay. The starter relay directs power from the battery to the starter solenoid which then engages the starter when you turn the key. When this is not working properly, you may notice intermittent starting problems as you describe. Generally, when this does fail, it does so very randomly and usually without warning other than intermittent starting. The power from the battery will still power other accessories such as radio, horn, etc., but you may not have any power to the starter. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your starter relay.
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