[Carbuff2]

A quick test of engine ground (and thus, body grounding) is to connect a jumper cable from the engine block directly to the negative terminal of the battery.

 

[Carbuff2]

Your fully charged battery should hold more than 13 volts.

"Holding" the charge is relative. The best evaluation of a battery's voltage is after it sits overnight.

I'll repeat this chart again.

Testing voltage immediately after driving (as when, you drive to a parts store and they measure voltage to test it) is a reason why many 'weak' batteries are not diagnosed.

 

[Carbuff2]

I think that more troubleshooting is in order.

EG, even with a new battery, the charging system should provide a LOT more than 3 or 5 VDC.

 

[Carbuff2]

Trouble shooting such as?

Current draw from the starter. (Not voltage...CURRENT)

ELD (Electric Load Detector)

Do you get the same voltage readings if you totally disconnect the present battery? Thinking shorted internal cell..

A bad cell could be damaging the alternator. Had that once, went through 3 junkyard alternators before I realized my NEW battery was killing them.

Unfortunately, I think you will need to 'dig in'....

 

[Carbuff2]

So ACCESSORY position it is okay, but when turned to RUN the voltage drops?
Or does the current draw only happen in the next position, START?