[lpf110]

I have a 2004 Mazda 3S w/2.3L engine. "Battery" idiot light was flashing occasionally for 2 weeks, and my dealer said the alternator and battery were bad. I installed (to save $!) reman Remy alternator and new battery and belts. Seemed okay for first 2 minutes then idiot light stayed on unless the revs were over 2000. Shut it down, and next morning took the new battery in to be tested, it was okay, so I reinstalled it and tried again. Light was off for 3 or 4 minutes, then went on and stayed on no matter what the revs were. On all occasions, the last step I did was to reconnect the negative battery terminal. Did I get a faulty alternator or is there some trick to this replacement? Thanks for the help. LPF110

 

[smokinAMD]

Is the belt tight? It might be slipping on the alternator pulley. Which would mean you have a bad tensioner. Also how are all the connections from the alternator to the battery and starter? Are they nice and tight and free of corrosion?

 

[lpf110]

Belts are new, and tensioner puts a significant pull on the belt so it does not appear to be slipping. Connections at alternator and battery are clean and tight. I have ordered a second replacement alternator, so I will take original and first replacement in to be tested at Advance Auto Parts. I did everything in the order in the manual, but maybe I should have tunred the key to "on" for a minute or before starting the car to let the electronics "reconnect"? (I am REALLY guessing here!) Thanks.

 

[smokinAMD]

Wouldn't have mattered. About the only other thing I can think of past the connections is maybe a bad wire somewhere.