Oldsmobile/Buick Repair: electrical, heater blower, battery test

Question
Hi;
   I have a question regarding a problem i encountered two nights ago.I was driving my car at night when i noticed my headlight dim a little,I had this dimming occur before.I checked my idiot lights and nothing came on.As iam driving now i engage my heater/blower i'm into this now 10 minutes when all of a sudden all my lights go off the tranny is not shifting and basically all my power is dead.Yet the idiot light for the battery doesnt come on.I kill all my power and hustle back home when eventually the car dies with a dead battery.Next day I recharge the battery,test it and is 12 volts,I drive the car for 4 hours without any problems,I put on a charging tester on the battery and see 14 volt charge,now with the motor on i put on the headlights and notice the charging voltage drop to 13v,next the heater and radio are turned on and the charging drops to 12 volts,still the idiot light doesnt come on.What do you think is route to take on this?
                                     Thank you
                                       Tom  

Answer
Hi Tom,
I think you have a bad connection in the wire from the alternator to the battery. I personally would load test the alternator at the output stud to see what it is capable of putting out, just to make sure it is up to par.
But if the charge can't get to the battery as quickly as you are depleting it, your battery will be drawn down, even if the alternator is charging, which could keep the idiot light off.
Check the connectors in the harness, and you are liable to find one kinda melted together, from the heat generated by a loose connection.

You didn't happen to mention what you are driving, But I have found this right behind, almost under the alternator on a Monte Carlo.
I have also found it on amp meters, and in the connector that passes through the firewall.

Van