Erratic temperature gauge

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <E0xiIg3-0005nu-00@iglou.com> "Douglas Hurst Quebbeman" writes:

> > There are several reasons why the idle controller will deliberately raise idle 
> > from 800 to 1100 or so.  Chief among them is low battery voltage - on some 
> > cars, vehicle motion is another.
> 
> When the engine is running, the alternator should be supplying the 
> electrical needs of the car, including the idle system. So why is it
> that battery voltage would play a role?

I didn't design the system - you'll have to ask Audi.  Perhaps Bosch told them 
that 800 rpm (times the pulley diameter ratio) isn't enough for the alternator 
to generate its full output?

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club