[Vwdiesel] pesky alternators, and the deep freeze

[Val Christian]

Here's an update on the strange problem I described a couple of days ago.

-the car got dried out with lots of heated dry air, and the instrument dash 
panel has not gone blank since then.

-the alternator which was discovered to have a failing (noisy) overrunning 
clutch was replaced with another AutoZone rebuilt unit.

-after tapping the starter a couple of times, the belts seemed to align and 
there was no observed tracking problem (and it was a good a dark night outside)

-car started on first tap, and the lights on the dash, including the ALT 
light were normal.  

-after a couple of minutes, there was a "burning brake smell" and I looked 
in the engine compartment, where the belt seemed to be tracking OK,
and feeling the backside of the alternator, there was no vibration as there
was in the failing alternator.  The case of the alternator was perhaps
90F-100F to touch.

I shut down the engine, and will go back out after the snow stops today.

Here's my plan:

1. Visually and tactilly inspect the serp belt.
2. Unplug the field winding on the alternator.
3. Put the smart charger on the battery.
4. Start the engine, and see if there is an odor.  If so, that would imply 
a mechanical problem.
5. If no apparent smell or mechanical issue, connect the field winding, and 
stop charging.  
6. Start the engine, and look at the voltage.  Possibly put a current probe
on the alternator output at the battery fuse block. (I think it comes in there
on an A4.)
7. Look at the AC component of the system, to see if perhaps there is a bad
stator winding or something catastrophic like that.

Any suggestions or comments?  The temps got up to about 14 yesterday, but 
the wind kept blowing away my kneepad, and the cardboard I laid on, even when 
there was an alternator sitting on it.  I have swapped perhaps 30 or so 
alternators (perhaps twice that!) and never had this issue, so it is new
territory for me.

Thanks.