Check the exciter wire on the alternator. It's the thin red wire. If it's OK, and that means pulling it off and putting it back on, then my guess would be that you need to replace the brushes. When they are worn below 5mm, charging gets weak and odd-ball things begine to happen.

Brushes come with the regulator/brush set from a dealer, about $70. OR, you can order a set of brushes only from an on-line supplier. I paid $2.00 each set for 5 sets (have 3 240's running). Installing them rerquires using an small soldering iron, some common sense and soldering skills, a bench to work on, and time.

If the alternator is not able to fully charge the battery, some strange things go wrong.

Good Luck,

Bob

:>)