Hello again. Forgive me for not searching hard enough to find the answer that is probably somewhere in all the threads...

I have an '83 300D that was overcharging the battery. I swapped out the voltage regulator and the overcharging stopped, but then it seemed like it was undercharging - never got above 13.7V when going down the road at 50MPH +. This morning no start until I put the battery on the charger. I went to the auto parts store and got a new battery (no $ charge as the battery is 2 months old). Now when I'm gong 50MPH+ I get about 13.2V (no accesories on). When I put the lights, defroster, and radio on the voltage drops to just under 13V. If I am at a stop with everything on the voltage is about 12V.

So, to sum up - new voltage regulator, new battery, maximum voltage is about 13.2V. Does this all sound like I need to replace the alternator?
I am pretty sure the answer is yes - I guess I'm just loking for one of you to confirm my diagnosis.

Thanks.

OK - so I think I know why the old regulator got cracked - there are 2 brass rivets that attach the black part of the regulator tothe white part - they are both contacting the alternator body and when I tighten the screws, the white plastic flexes. I just put a couple washers between the regulator and alternator so the screws are tight with no flex on the regulator, but the voltage seems the same. This is the Bosch regulator. Do I nead the other kind that is for sale here?

The above pic it the connector from my Alternator. You shoud get voltage from those 2 spots all of the time.
Yes, there is a bunch of different Bosch Regulators and a lot of them look almost the same
Below is an article concerning Bosch Regulators and a thumbnail pic showing the Ground Tab on the Regulator (if the contact area under the tab is not bright shiny metal it may not ground well and I do not know what effect washers under it would have).
The article below tells of some aspects that have an effect on the Regulator.
http://www.detomaso.nu/%7Ethomast/alternator/

Also a bad ground of that Alternator to the rest of the Engine through to the Battery can also can cause charging problems. Some have run one of their Jumper Cables from the (-) Batter terminal and grounded it to the Alternator Casing to see if it charges better with a better ground.

I have also read that the charging indicator light must have about 3 ohms of resistance to it for the Alternator to charge correctly (the smallest slot on the left goes to the Ignition Switch and Charging Lignt; no voltage there until the key is on).

Attached Thumbnails

   

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84 300D, 82 Volvo 244Gl Diesel