alternator drain on 2000 Volkswagen Jetta

i just put in a new 120 amps alternator and its coming up on the computer as a bad alternator. I dont know what to do any suggestions? thanks guys

Asked by for the 2000 Volkswagen Jetta
What is the problem you are having? And what type of test are you performing on the alternator?
Thanks for the reply, but to be able to advise you, I need to know what the original problem was, and what the problem is now. Are there any battery lights on? Is the battery OK?
i have a black and decker battery charger and it has a alternator tester
2 more answers
Could be a defective alternator have the parts store check it with their alternator test machine
maybe its telling you there is no alternator charging occuring which could be other than an alternator. does the battery light in dash light with key on, eng off? this circuit is important to "excite" the alternator. check the bulb and wiring (think wire is blue) if no light.