Also, with respect to the alternator concern, I am able to reduce the current flow to zero by removing the two fuses listed in the original post. If the alternator, cables, etc were the problem, I expect that I would still see a parasitic drain - am I thinking about this correctly?
I donāt know about YOUR concern . . .
MY concern is whether the alternator was properly tested
It involves a little more than just running a 12V test light across the battery terminals while the engineās idling with no loads . . .
You and I are talking about 2 different things
Youāre talking about the alternator being the cause of the excessive parasitic draw. Unless I missed something, it doesnāt say anywhere that you waited, say, 30 minutes after connecting your multimeter inline between the negative battery cable and terminal
Some modules need a LONG time to go to sleep
hence, Iām not even sure you have an excessive draw at this time
My concern is the alternator . . . to be specific, Iām concerned itās not really keeping the battery fully charged.
To be blunt, Iām concerned Firestone didnāt properly test the charging system. Even a mediocre alternator will show 14V across the battery terminals at idle with no loads on
Test it properly, though, and it may fall flat on its face . . .
your carās old enough that the alternator may be failing
By the way, did anybody bother testing just how many amps your alternator is putting out at the specified rpm with the tester, using the proper test procedure . . . ?!
Not sure, but point well taken. I am obviously not a mechanic and trying to troubleshoot, so I appreciate your insight. I will check the charging voltage. I do not believe I have the equipment to check the charging amperage, but will verify this with Firestone.
The car is being driven very little - maybe 20-25 hours/week. Could be a contributor to the battery not being fully charged? I will plan to drive it for an extended period and check the battery voltage to make sure it is at full charge.
BTW, I am using an ammeter between negative cable and battery terminal. I have checked this for for several hours to make sure that everything is asleep. It seems to stabilize at 80ma draw. I can make it go to zero by pulling two fuses.
20-25 hours a week is actually a lot of driving, if thatās what you meant?
You sure you didnāt mean 20-25 miles a week . . . ?!
You only pull one fuse at a time . . .
yes, only 20-25 miles/week. Yes, I pulled each fuse one at a time. ECU-ACC dropped ~60 ma, so this seems to be most of the draw.
You will get many answers of how much amperage is acceptable for a draw test. It really depends on the year of the car and make and model. In days of old 50 ma was rightfully the limit. But now days 80, 90 or even 100 can be normal. The highest Iād want to see on any car would be 80. My daughter had a car that did what yours is doing. But a lot worse. I did the draw test and it said good. Battery was good, alternator good. Upon longer test period I found that the rear windshield wiper motor would randomly self energize. Found out it was a known problem. Replaced motor and it solved the issue. I donāt remember the year, make or model, but you might want to check online for some common anomalies with your vehicle.
Goss, in a video attached to another thread, says 20 to 30 minutes at highway speed once a week will keep batteries charged. Youāre driving 20 to 25 hours a week, which should be way more than adequate (assuming itās a highway speed).
Thanks, Ramazz. I typed that in error. The car is sonly being driven 20-25 minutes/week. These are short trips in town, so speeds are likely averaging 30-35 miles/hour.
The OP is quite concerned about parasitic draw while a number of us are quite concerned about the alternator or the battery. How about this plan:
- Using a real battery charger, charge the battery fully. Measure that voltage after the battery cools.
- Disconnect the two fuses so there is absolutely no parasitic draw for a couple days.
- Now measure your battery voltage. Basically, it should not have budged. Remember that if the battery voltage drops to 5/6 of the full value, that a bad cell is indicated.
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thatās not exactly a good situation. Those short trips are slowly but surely running down your battery
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For the alternator, I have let the car run at idle speed, and voltage measured at the battery is ~14V. I ran the car for approximately 15 minutes at idle. Battery voltage was at 12.4 V before charging. After charging for 15 minutes, the battery was at 12.8V.
What other steps are recommended to check this?
Thanks in advance.
Let the battery cool after charging, and measure the voltage. Then pull the two fuses and watch the battery voltage for a 2-3 days.
I would still prefer a battery charger. You did not necessarily find the highest value for the battery voltage in just 15 minutes, unless your battery was already very near full charge.
The battery and charging system are fine.
Thereās a parasitic current draw.
Period!
Tester