Alt voltage steady, but lower after servicing
 

The voltage on my 85.5 alternator just went down after servicing (new regulator and bearings) - but is steadier.

Used to start at just over 14 volts, but usually within a few minutes the voltage indicator needle would start to waver between just below this level down to just above 12 volts. Obviously time for a new regulator, and I decided to do bearings also (sounded squeaky when turned by hand).

Now, the voltage seems very steady....but is running just over 13 volts. Does this sound about right? And why would the voltage have started up over 14 prior to servicing?

Bosch VR usually will be set at 13.5 to 13.8V output.

Depends on the VR you installed and removed--OEM or Aftermarket?

RPM also changes the output.

Cable and wire corrosion on the battery, cables, grounds and connections change the output.

Did you clean, dress the alternator slip ring for the VR?

???
J_AZ

As above. Do you recall size/part numbers for the bearings? Source? I'm gonna need to do this soon on my 84.

Cheers!

I'm with John on this. If you put new brake pads on a badly grooved rotor, braking effectiveness won't be very good. The same thing goes with a new VR. If you haven't dressed the slip rings, you're going to see wierd voltage issues.

This Pelican link has a lot of info on rebuilding an alt and parts source:
Lots of pictures for Slam & son!
A 964 is a '89-'94 911- got that from Google ;) Close enough.

http://forums.pelicanparts.com/porsche-964-993-technical-forum/686617-964-alternator-rebuild.html

The Wagner Alternator parts link in the post is old. This works:
Wagner Alternators and Supplies, Inc.

Look at the parts links from Bazar01 also. (and others)

GL
J_AZ

Perfect! Thanks, John. Armed with this knowledge I can just pilfer the bearings out of any 911 I find on the street in as little as 4 hours! Just gotta figure out where they hide the engine...