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Discussion Starter #1
Gentlemen,
Our 2007 has a new parasitic power problem. Battery is well charged and alternator shows 14.3 volts running. There is a parasitic power drain of 5 amps. I have read .050amps (50 milliamps) is OK. I have sequentially removed both the interior and under hood fuses with no affect except for the interior panel fuse labeled "room lamp". Removing that fuse reduces the power draw to 2.5 amps. I disconnected the alternator to check that unit with no change from the 5 amps draw. Any ideas where to look next? Thanks!
 

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The most likely culprit for parasitics on any Nissan is the AV Unit (radio). The next most likely is a bad diode in the alternator. That said, you need to understand that the car will only fully "hibernate" after 30 minutes with the doors closed and everything off. That means draw checking must be performed with the door switches disconnected, so you can access the inside fuse block without waking up the BCM. Once the car hibernates, 50mA is high. Healthy I-key cars draw no more than 20mA, even less for a car with lollipop keys.
 

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Discussion Starter #3
I disconnected the alternator and the 5amp drain was still there. I understand the systems remain charged for a period of time and also change on reapply power. Initially reconnecting the amp draw is 25 or so diminishing over a few minuets to the 5amp consistent drain. I clamped the door interior light switch to shut off the interior lights with the door open. The "room light" fuse was the only one that reduced the draw but only down to 2.5 amp. The radio does not appear to have a designated fuse but perhaps removing it and disconnecting the power cord would show something. Thanks for your suggestions and reply. This car has been really good since new and we would like to hang on to it.
 

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The radio definitely has a fuse, but it will be in the fuse and relay box under the hood, not inside the car. The fuse for the alternator exciter circuit should be in the same box. I'm a bit confused by your numbers, there's almost nothing on the car that can draw 25A besides the blower and headlights. Are you maybe missing a decimal point? 2.5A on "wakeup" is pretty normal and 0.5A would still cause plenty of problems as a draw.
 

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Btw, pulling the screws and simply removing the door switches is generally easier than trying to keep them down with tape.
 

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Discussion Starter #6
My foolish mistake. I was using the wrong scale. Wake up amps starts at .517. A few seconds later with a click .426, then .213, 141 and holds at a fluctuating .137-.141. Yesterday, although on the wrong scale, I did sequentially remove the under hood fuses with no effect. Perhaps that would cancel the radio as a possible problem.
 

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That "stepping down" is perfectly normal behavior, once they hit 100~150mA they'll hold at that level for the rest of the time until they hibernate. On most models hibernation will occur at exactly 30 minutes from the time the dome lights go out with everything off. The hibernation clock is usually very accurate. At that point it should drop from 100+ mA to about 10~15mA. If you don't get that final drop, something is preventing the BCM from hibernating.
 

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PS - Many times pulling fuses and then re-inserting them will cause the BCM to wake up again, which complicates the heck out of trying to trace a small draw. It's generally the best practice to take a pic of the fuse locations, then pull them in sequence without re-inserting any.
 

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Discussion Starter #9
The Body Control Module appears to be powered by the one interior fuse that lessens amp draw but doesn't eradicate it when extracted. I'm thinking a simple battery disconnect switch on the negative battery terminal may save the battery.
 

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I'm thinking a simple battery disconnect switch on the negative battery terminal may save the battery.
That's always an option. Since the problem is a failure to hibernate, there's a good chance the BCM is itself the culprit, but if all its other functions are normal then there's no harm in simply disconnecting the vehicle.
 

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Discussion Starter #11
I added a NAPA disconnect at the battery that works fine. One other question is if the Body Control Module or the Intelligent Key System is staying "awake" for what ever reason, might that be the reason for the continuous parasitic draw? Thanks!
 

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One other question is if the Body Control Module or the Intelligent Key System is staying "awake" for what ever reason, might that be the reason for the continuous parasitic draw? Thanks!
Yes, no doubt about it. In fact, given the low level of the draw, I'd say something south inside the BCM is by far the most likely culprit.
 

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Discussion Starter #13
One last perhaps foolish question. On reconnecting the battery, is there a time period of the car "relearning" information that would cause emission checking to go astray? Does the car need to recycle speed, heat, etc before a emission checking program? Thanks!
 

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No, the only info lost when you disconnect is automatic power window and moonroof calibration, so if the car has them they need to be re-timed. No engine or drivetrain data is lost.
 
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