1985 GMC S15

Electrical problem
1985 GMC S15 6 cyl Two Wheel Drive Automatic 360k miles

Ive had the alternater checked and the battery checked and both checked out ok. I replaced my fuses and diconnected my amp. My problem is, my battery keeps draining. With a boost, itll crank up and continue running. However, the battery dies out and all electronics with it. I need to know how to find the reason and fix the problem.
November 2, 2010.

Does this happen while it's being driven or after it has been parked overnight?

Nov 2, 2010.
Was your charging system checked with alternator on the vehicle? Does the battery have a full charge, if not take it off and get it charged. Use a digital multimeter across battery posts, everything turned off. The generic spec for a fully charged battery is around 12.6 volts. Then start the vehicle, take second reading across battery posts, the second reading should be higher than the first, if the charging system is working.

Nov 2, 2010.