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Q: Alternator not charging

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I've replaced the alternator twice and the battery as well as the connector to the alternator but it still won't charge

My car has 171000 miles.
My car has an automatic transmission.

A: The alternator charging rate is controlled ...

The alternator charging rate is controlled by the engine control module under the air cleaner housing. You should disconnect the battery and check the connections at the engine control module and look at pin 54 on connector one (C1). It is a grey wire that goes to the alternator to control charge rate. Put dielectric lube on connections and reinstall to see if vehicle charges normal at 1200 RPMs. If not, then have vehicle scanned to see if ECM is controlling charge rate. If you are still having trouble, a certified mechanic, such as one from YourMechanic, can come to your car's location to diagnose your vehicle's charging issue.

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