Hello
Recharged battery, shows 12.6V. Starts well, idles well, and after ~10 minutes all dies with not enough voltage for cranking, measured voltage is ~9 V.
Put another battery, same story. Measured voltage while engine running : never reaches 13.8V nor above 12.6V = Alternator not charging.

How to find if failure is brushes, internal regulator, rectifiers, stator, rotor, open connection or else ? Inside fuse 24 tested OK. Belt is taut. Electrical system of all vehicle is unmolested original that never gives trouble.

 

Brown wire has to be the output of the alternator as goes to a 150 Ampere link, but it is not connected to the cathodes in the alternator (?)
White wire to the alternator appears to be the 'enable' connection for the alternator to work, Is it ?
Is the brown/yellow wire to indicate 'not charging' light on the dash; is that right ?
Correct me, please.

 

Disassemble and look at brushes, I did a thread on it in last two years. Search on keyword alternator and me as thread originator.

 

If it is like the D1 system, if the light bulb (J100 on diagram) is bad, the alternator won't charge. Weird, I know. I keep a spare in my trail parts bag.