I need a new Alternator for my Roadster. My Roadster is an 04 and currently has a NAPA Alternator that is going bad.
Any suggestions?

 

No specific brand per se; but I've used rebuilt and remanufactured alternators over the years (not just Nissan). Remanufactured units, while more costly are generally a better option due to the fact that the entire unit is disassembled and fitted with all new parts. I put one in an Infiniti a number of years ago and when the car said goodbye to us, the alternator was still fine after another 100k on it. I hear more not-so-great things about rebuilts in the shop as the rebuild process usually only includes replacement of a diagnosed bad component, e.g. armature, internal regulator, etc. But, they are a lot less expensive. FYI, the OE units are Mitsubishi so I'd say that a remanufactured OE unit would be a safe bet. (Or, shop around and find a new OE unit. These run around $4-500 last I looked.) Best to compare warranties. Most reman units are a year or so.

Also might want to check your NAPA warranty. As a supplier to our shop, have found them to be pretty cooperative and (some of) their reman units do carry a lifetime warranty.

There are also "high output" replacements available but generally speaking, unless you are running accessories that require the higher output, e.g., gonzo stereo setups, a stock output alternator is more than fine. HO replacements do require modifications most of the time, e.g. shorter belts for the often smaller diameter pulleys, upgraded wiring - lower AWG (thicker, heavier wiring to handle increased current load, etc.)

 

Go with a remanufactured OE unit. The VQ35DE units are much more expensive for some reason. I wouldn't trust the aftermarket options out there. Maybe I'd be willing to give Bosch or ACDelco a try, but stay away from local parts brands and the made in China stuff (WAI Global, TYC, etc.)

The OEM reman unit is over $500. You can get that knocked down after sending back the core.
The P/N is 2310M-CD010RW

I chose to rebuild my OEM alternator in my garage (I wrote a guide on this and posted on these forums). They aren't very complex components, but the process is time consuming. Still, I trust my rebuild skills more than a sweat shop in Mexico or China. You just need to use quality components (bearings, brushes, regulator). Usually the stator, rotor, and diode pack aren't the cause of a failure.
Cheers!
-Icer