The charging circuit on my 1982 300 TDT is only putting out about 13 volts. If I put a voltmeter on the battery I get about 13 volts measured. Then if I start the engine and rev it up, I can see a slight increase, like maybe .2 volts, but not what it should. On my two Toyotas the alternator ups the voltage up over 14 volts.
I have a replacement Bosch alternator I bought from a Mercedes dealer. (I had a back injury and the alternator went out when I was on the road on a business trip, so I had to have the dealer replace it. $$$$)
I took the voltage regulator/brush assembly out today. It shows a little wear, but the brushes are still pretty long and it looks fine. The red idiot light for the alternator comes on when I turn the ignition on, and goes out when the engine starts and stays dark when I drive along, but the system is not putting out enough to keep the battery charged, especially if I run the sound system and use cruise control and have the automatic climate control engaged.
Does anyone have any ideas of what tests I should run? Or any other suggestions?
Thanks.