Am I really just that retarded or what?
I have a new alternator in my car (1990 300zx non turbo)
and within 40 miles, it has crapped out on me.

The alternator is a reman'ed unit from Will's Alternator and Starter. I've had good work from them before so I don't think it is just a bad alternator.

I put this alternator in and it lasted about a month the first time.
The engine has that annoying Cam seal oil leak, so I wrote it off as the leak must just be worse than before and the oil killed the alternator.
Pulled it out, took it to the shop (again, Will's Alternator and Starter) they torn it open and said that oil had gotten in it, and caused a diode to burn out. They cleaned it up, and replaced the diode and said it was good to go.

I re-installed it. Made a little shield thing to keep the oil out of it. charged the battery and went for a test drive. Everything seemed fine.

Today, I was driving it around again, and started noticing that hesitation that happens when the fuel pump isn't getting enough power. Awesome.
Get home, break out the volt meter and low and behold, it is at less than 12 volts.
Pull the negative off of the battery and the engine stalls. awesome.

Looking at the alternator, not even the shield has any oil on it yet. So I'm having a hard time believing that a drop of oil killed the alternator again. Especially so fast.

So, any suggestions?
Feel free to point out the obvious. I seriously am thinking I was just retarded and didn't do something correctly or whatever.

 

Best suggestion, take it to the closest autozone (with a fully charged battery or it out of the car) and have it tested. Just because it's "new" doesn't mean it can't fail or be bad from the factory.