$%#$!!! Battery!!
 

Battery keeps going dead. when fully charged starter still turns slow...real slow. and the battery light on my instument cluster lights brightly when reved high, but not noticable when at idle.. These bats are expensive. Please help.

Get your battery and charging system tested.

How do you know the battery is fully charged?

Also, have you checked the acid levels in the battery's cells? Should cover the plates and a bit more. Top off with distilled water.

Clean the mating surfaces of the battery terminals and inside of the battery cable clamps, reassemble.

If the battery won't hold a charge, have you checked for a current drain on it when the engine is off? Some things, like the power antenna, are prone to failure and can draw amps out of the battery constantly. Sometimes the alternator diodes go and leak, reducing the alt's effecitveness and becoming a current draw on the battery when then engine isn't running.

With the alt light behavior, I'd suspect the alt ground or engine ground.

Check the alternator belt tension. Also check all the connections to it -- look for loosness or corrosion, or just skip that and remove them all, clean the mating electrical surfaces until bright and shiney, and reassemble using dielectric grease.

Also, sometimes the voltage regulators brushes wear out and fail to make contact, but then the alt light usually behaves differently.