Discharging Battery

[CudaHead]

I just went through a similar problem this week. When the car was turned off, the battery was discharging.
I also was using a alternator bypass wire and after market A/C.
By removing wires from the Starter Relay stud one at a time and watching the voltage, I  traced the problem to the Alternator.
When the alternator wire was off the relay stud, the voltage stopped going down.
I tested with the wire off the alternator but still on the relay stud, it was fine also.
I replaced the alternator and the problem was fixed.

[Rich G.]

If you put the test like between the negative battery terminal and cable and it doesn't light then nothing is drawing power. Open the door and have the dome light go on and the test light will light showing a power draw. If it goes out when you shut the door and the test light goes out showing no draw you probably just have a dead cell inside the battery .

[Caparco]

Thanks for all your help guys, finally got it fixed!
As I thought it was the alternator! What was happening was they bench tested it , at low rpm, but at high rpms the 2 plates (inside)  were separating from the wire core sandwiched between, wasn't till I had another person with me seen sparks coming from the alternator as I gave it higher rpms.

Course my wire work wasn't the best either , shortened some the longer lengths and secured up connections.
Was so relieved to see 14v's !! And hold steady