Could the alternator test bench at an auto parts store be wrong?

The new alternator tests good at the store, but when it's in my car, it doesn't function properly. The battery light is on and its draining the battery. Could the test be inaccurate?Could the alternator test bench at an auto parts store be wrong?
not likely.you don't mention make,model, voltage regulator, grounding problem etc,,, is the amperage of the battery enough for your car! however i would say discharge problem,ie.alternator/regulater! i bet it's the latter!Could the alternator test bench at an auto parts store be wrong?
try disconnecting the battery while the car is running( both pos and neg) if it keeps running your alt is probably good if it dies immediatly you probably have alt issues...old school way of testing alts

good luck!Could the alternator test bench at an auto parts store be wrong?
no prolly not wrong...make sure ur belt is tight enoph...and make sure u got ur wires where there suppose to be...maybe there's a short in the wires that go to the alternator from the battery...
Could the test be inaccurate?



At a store, definitely.



Is that a safe way of testing it?



NO!



could that damage something?



YES!



Unless your car is 50 years old, and doesn't have any solid state circuitry.

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