Which auto parts stores have free diagnostic services?

None. Autozone will let you use a tool to scan the computer and pull a code if you have a check engine light. But no part store can give you any kind of diagnostic service, because that requires actually working on your vehicle and they are parts salesmen.

After you have a code you will need to know what that code means and then perform a diagnostic service for that system before you can find out what it wrong.

Do a search for free check engine light or something like that for more information.

Actually you cannot properly bench test alternators, they should be in the car. You might end up replacing a good alternator or replacing a bunch of other stuff when it was the alternator the whole time but bench testing told you it was ok. But they do offer that service.

What is important is to find someone who will diagnose the problem for you and will explain what tests they are going to perform for the price you pay.Which auto parts stores have free diagnostic services?
Most auto parts stores can pull a trouble code out, and try to sell you a part the may or may not fix your problem, but most likely won't.



Or many shops will pull a code for you for free. there can be many different causes for the same code and someone that is untrained or doesn't understand the operating principals of the system will end up just hanging parts and costing you more money in the long run.





So either take it to someone that will diagnose you problem properly for a fee. Or go to autozone and buy an oxygen sensor cause that the problem right.Which auto parts stores have free diagnostic services?
Just about all, if you are talking batteries, alternators, and code reading...Which auto parts stores have free diagnostic services?
Auto Zone
All Autozone's, Oreilly's and Advanced auto parts can diagnose batteries, alternators, starters, and hook up a code reader to determine a service engine light or warning light problem.

pick a part