98 GTP: Leakage current

If the car sits for, say, a week or two, the battery dies. This has been happening for a long time but only getting around to diagnosing it now. The ammeter on my DMM shows a very slight current (7 micro-amps uA if if I'm reading the meter correctly) with the car off. That seems pretty small.

I have isolated the source of the current leak to the alternator. After disconnecting the alternator battery (charging) terminal, the ammeter goes to zero.

I'm looking for some warm fuzzies that the amount of leakage current explains the dead battery before I replace the alternator. Car has an Optima AGM battery that is supposed to be 50 Ah. Seems like it would take a very long time to drain the battery at the low leakage rate. But can't understand why there would be any leakage current through the alternator.

(I've got a couple active threads as I'm trying to fix a few nagging problems with this car: See my other post on P0341 (ordered CMP sensor today) and P0171.)

As always, any guidance is appreciated.

Scroll down to: FINDING THE CAUSE OF A KEY OFF CURRENT DRAIN


http://www.aa1car.com/library/battery_runs_down.htm

Scroll down to: FINDING THE CAUSE OF A KEY OFF CURRENT DRAIN

Last thing I did was disconnect the alternator and reconnected the battery. I'll check battery voltage over the new few days to see if it holds a full charge. (Charged the battery over the weekend.)

7 micro amps is basically, zero......

Most cars today, should not have more than 25-30 MA, or milliamps.....

25 milliamps is 0.025 amps.....

25 micro amps is 0.000025 amps....

If you were to shut everything off in the car, doors closed, key out of ignition, hood open, under hood light disconnected....then.....

Disconnect the neg terminal from the battery.......if you were to install an amp meter in series between the battery and cable, you should get a high milliamp reading, because all modules have been awakened.......then over time, the modules go to sleep, and you get a true parasitic reading.....on a Park Ave, with all the modules it has, it could take up to and over 10 minutes for the modules to go to sleep.......

For example, everything is off.....now, you insert the amp meter...get a reading of 300 milliamps.......but after a minute, it may drop to 200 ma, and then a minute later, to 100 ma, and then finally it drops to around 25 ma, which is acceptable....on some cars with OnStar, the module will randomly communicate with a satellite, and create a surge in amperage for awhile.....this is normal....

If you saw the initial 300 ma, you would think you had a draw and would be chasing your tail......

How old is the batter? Better double check that reading...7 micro amps, or even 7 milliamps is not a draw....

That amperage is very low. Maybe I was using or reading the meter wrong. But I've got bigger problems to chase right now!