Dead battery - Is the alternator bad?

[cas951]

3point2,
Your chrging seems fine to me. As long as the Alt output is 14+ volts with no load you should be fine. If you want to test further let the car idle, turn on your lights, AC, and other accesories to see what voltage you have at the battery.

You should have 13+ volds.

What you have is a drain when the car sits for awhile which drains your battery. This is why Ian and I suggest you use the voltmeter and pull your fuse out 1 x 1.

If you don't find the culprit from the fuse the likely cause is either the starter or Alternator or bad Ing switch.

[Ian c]

Indeed .
I suspect he's decided to give up and go get drunk

Hopefully he'll be back tommorrow and we can carry on with the online diagnosis

An alternator and voltage regulator can be working fine yet not put out enough volts to charge a battery .

The fact his is putting out enough on its lowest reading (2nd test = dropping) , and his battery DCv reading went up indicating a fuller charge , leads me to look at other things as I mentioned in my "best guess" post .

I had a read back earlier, and depending on the mA drain test results , the ignition switch is edging its way towards the number one on my list ....


(Radio fail)