another not charging thread

Mattax said
Yes. It means current is flowing through resistance. How much discharge was the ammeter showing?

Well, the ammeter on this car is long gone, it was in pieces by the time I got the car and the previous owner spliced the two wires together. I'll have to follow the circuit at some point and look for any corrosion.

Mattax said
At the alternator output terminal or the battery?

Both locations show under 13v, though I think I saw over half a volt more when probing the alternator output.

Mattax said
When 67Dart273 sees this he's going to yell at you.... not to do that!
edit. Beat me to it!

However since you have done it. It does not mean the engine is running off battery. You were correct in your first thought. When there is no ground connection to battery, the battery can not provide power.
For current to flow it needs a complete circuit.

Noted! I'm a little confused though. I had put both the negative clamp AND the jumper wire on the negative post, just to clarify, and then I took off the negative clamp WITH the jumper wire still on the post and engine kept running. As soon as I removed the wire the engine stopped. Doesn't this mean it was taking power from the battery? (I won't do it again 67Dart273)