Alternator Bosch or Duralast

I recently replaced my alternator on one car w/a new Bosch unit. Cost about $200 and took me a couple of hours. Dealer cost just for the part was $700 and with book time they priced it out at over $1,400.

Bosch Alternators have 2 posts on them, the big one is for main battery ground, the smaller one is for the exciter or blue wire. When the cars ignition switch is turned on, the Dash light (led and diode) applies 12V+ to the coils to excite them, so the alternator can produce a charge. When the Alternator is producing current and voltage it goes to 13.5-14Volts.

Just bought and installed a Duralast Gold from Autozone last week for my '07 9-5. It has a little whine at 2500 RPM but works better than OEM. Has a lifetime warranty and it's 100% new too!

When my alternator failed in my 24v, I replaced the alternator with a duralast, replaced the harness and fuse panel with OEM parts, and 50k later it's still working like a champ.

From personal experience, I'd recommend the duralast gold alternator from autozone. I originally got the duralast regular alternator but I had to change it out it least 2 more times under warranty. The last time I just decided to upgrade to the gold version since I was sick of replacing the alternator, and it's been great for over 2 years now. Remanufactured ones are usually junk, get a new one like the duralast gold one. FYI what usually gives out first is the built in voltage regulator, that's what went wrong every time with the cheaper remanufactured alternator. There might be other good ones out there but that's my experience

The part # for the Alternator (Automatic trans) is 6H903016L and it's made by Bosh. [Europaparts](https://parts.audiusa.com/p/Audi_2012_A4-Base-Sedan-20L-AT-Quattro/Alternator/48001649/06H903016L.html) sell's it for $499.95 (OEM).

I just bought this car and I was about to replace the alternator belt but realized it’s not aligned. From this prospective the alternator is too far to the right

Duralast Gold = new manufacture. A new unit from China. Sometimes OK, but often crap.

Ive had a few Bosch reman failures lately at my shop as well, although they were for N52s, all bearing noise after about a year.

Symptoms: Flickering lights, and occasional hiccup start. Now battery light is coming on and staying on. When stationary battery tests around 12.5 volts. When running, that drops to 11.7 volts.