Why is it that every Alt I see has the green band? Is that the copper/ nickel oxodizing? just curious..

 

mine has a brown band......

 

I'm not positive on this but I think it is a factory designation for amp output (i.e- Delco may have a blue band for 60amp, green for 70amp etc). Probobally helpful for rebuilders.

 

I am not sure about that because it was't there until the car sat for a while...

 

If it's in the same place as the colored band on this alternator, it's paint. I think i know what your talking about though..There is a vented area where the copper windings appear, correct? If that has oxidized, somehow you are getting some dampness in your engine bay..

 

Here's a good comparison of a stock Toyota vs an aftermarket upgrade. The stock alt has the windings exposed to allow heat to escape. The aftermarket is sorta 'sealed' with cooling fins..Notice neither has a color band in this case.

 

mine is green paint

 

Yeah....I used some scotchbrite and then painted it black.......probably just oxy...