Hey folks,

Just a quick question here that I can't seem to drum up an answer to in the FSM or via some searches:

Are the alternator pulleys between the S5 NA and Turbo alternators a different size?

I'm pretty sure I had a turbo alternator from a junkyard from a long time ago, and I've just swapped it out with a big 135A one that is sold on Ebay, but I am getting a voltage drop at idle, down to 11v or so. Lights dim and everything. Just try to factor out possible causes; if the turbo pulley was larger, that'd explain it ...

 

No, the pulleys are the same.
I'd suspect the super-duper eBay alternator.