808burn

I have an '86 GXL and she was starting and running fine for a while. A few days ago I go to my car and it acts like the battery is dead and won't start. I jumped it and went to work. when I came back out of work 8 hours later, it had the same issue. So once again I jumped it and it started. The other day I went out to start it and the same issue again, but htis time when i jumped it, it didn't start and even with another car jumping it acted as if the battery was totally dead. Now the battery is an Optima red top, and is only 4 months old. When I get into the car the tachometer is dead, the car makes a double beeping noise constatnly, but only when the car is in gear and driving. When not in gear adn driving the beep doesn't happen at all. When i put the key in the ignition and turn it to the ON position, the lights in the center with the add coolant lights and what not all come on, and when I turn the lights on only the running lights come on, but the gauge lights and headlights don't. The car won't turn over either. But we tested the battery and it shows it has charge. What could this be? I need help really quick and really bad.

SureShot

Battery cables an connections. Both hot & ground.

VOLTAGE TEST
Engine running, headlights & heater fan on high:
Alternator post to alternator frame = 13.5-14 volts (verifies the alternator output)
alternator post to battery (+) = 0 volts (verifies the primary + wire)
alternator frame to battery (-) = 0 volts (verifies the primary ground)

Any voltage drop across those cables is a bad connection.
Sometimes the bad spot will get warm.

808burn

I think I might have found the problem. I went through all the fuses and replaced a few and then I tested the battery. The battery didn't work in my other car it was totally dead, DAMN OPTIMA RED TOP BATTERY!!! It isn't even 4 months old!
What a piece. Oh well.
Getting a new battery here in a bit and will see if that really is the issue.

robfeltner

an easy test for an alternator:

Start car, then disconnect the ground from the battery. Car should still run. If it dies on the spot, it is definitely the alternator, and probably the condition of your cables as suggested. With the ground disconnected, and the car running, you should rev it up a little, because the car will generate more current at higher rpms, but also draw more current. After that, turn on some accessories and see what happens. All this takes about a whole minute and costs you nothing. Worth a try anyway.

Rob