Charging issue - 1985 300D (Cali.)

[nate300d]

My 1985 300D (Cali. version) has a charging problem, but what I do not understand is how it affects the car. Not only is the alternator light lit, but also the brake light, brake wear light, and the fuel reserve light. When you start the car all of these lights are on. As you rev up the engine they will fade down. Once in a while all of the lights will go out as if it is charging. If the alternator has a problem why are these other lights lit?
I purchased this car from a friend and he had installed a rebuild alternator. I am wondering if the problem may be a connection or the regulator on the alternator.
Any thoughts?