How much amperage can an alternator support? no really...

[Huw Powell]

Some of my answers have alreayd been covered, but...

> My cooling fan is on a manual switch and I typically run it always-on
> (eliminates one more point of failure in the temp-switch). Any idea what
> amperage that draws?

Well, it's on a 25A fuse, so probably 20-ish.  But that might be a 
startup peak, it might draw less while running.  Want to really "know"? 
  Hook up an ammeter that can handle over 25 amps to it.

> I've heard people say the alternator has to 'work harder' given the load
> - I don't understand how a device on a pully system that varies in speed
> based on engine speed 'works harder' given a greater draw ? Doesn't it
> continuously do the same thing - but its output is regulated according
> to need? Will the alternator wear out sooner the more power it needs to
> produce?

With no load, the alternator takes almost no effort to spin.

As load increases, the physical resistance to spinning goes up (wears 
belt faster), because the opposing magnetic fields in it are stronger.

You might also want to search out a VR that yeilds the highest voltage 
possible - Bosch seemed to think that anything over 12.7 volts (ok, 13) 
was risky, but the one in my 90Q runs almost 14, as does the one in my 
coupe.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/