A healthy battery reads 12.60 or better at rest and surface charge has bled off. That's accomplished simply by letting the car sit for 6-8 hrs. before checking with the VOM.

You can get a fairly good idea how well off the brushes might be and the alternator when you start the car up cold in the morning; testing with the VOM. You can also do as Larry Bible suggests and simply pull the brushes for examination. It takes more time to setup for this than it does to pull, examine and reinstall

I was seeing about 13.90 in an orig. 13 yr. old Bosch alt. After driving 30 miles or so, it would read around 13.25-13.35 - in the summer. Alts. lose a bit of punch when things have warmed up.

I decided it was time to change out the alt., due more to it's age & not wanting the better half stuck out on the road. I replaced the 80 amp Bosch AL66X with a 100amp Bosch AL166X.

That was 6 mos. ago. After the upgrade, I was seeing 14.35 at idle when cold. Am still seeing this same reading taken on a cold engine at idle.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"