[Submariner409]

What voltage does the DIC show at Key: ON? Should be 12.4 to 12.6 volts - battery voltage. After START the system voltage (alternator charging and carrying car electrical load) should ramp up to about 14.2 to 14.8 and stay there.

Set the VOM to Volts DC and connect to a positive 12 volt source and a body ground.

A fully charged "12 volt" lead-acid battery should show 12.6 volts when disconnected from anything for a half hour.

 

[Submariner409]

NEVER disconnect the battery with the engine (alternator) running - the risk of severe electrical system damage is almost 99.989%. It's a wonder that, when the voltage regulator saw 0 load, it didn't spectacularly self-destruct.

If the battery has a dead (shorted) cell it will go practically dead overnight.

Anything below 12 volts is essentially dead. Some plate voltage, no amp power left.

 

[Submariner409]

Thanks for the vote of confidence - but please understand that some of us are here to pass on knowledge gained from many years of wrenching - in my case, since about 1953 or so. Preaching hearsay, rumor, innuendo, ideology is nonproductive - actual fact and experience is the basis of true knowledge.