Parasitic current draw.

I know that this thread is nearly 3 years old (since last posts), but Don's problem is very, very like my own (minus the aftermarket iPod interface), and I have seen few so similar.

Don: how did you resolve your current leak issue on the DOME fuse circuit? Was there in fact a problem with your SKS? (You said that disabling it with the switch under the steering wheel did not change your current leak amount.) Thanks for anything related that you can recall!

I have 12-28mA (very jumpy) of current leakage through the DOME fuse circuit on my 2005 Gen2, measured at the slot for that fuse after pulling it and waiting 20 minutes, doors closed and locked, nothing turned on. My SKS is disabled with the switch under the steering wheel. (There is another 11-12 mA that leaks even with the DOME fuse pulled.) With the DOME fuse in, the total leakage (again, after waiting 20 min, etc.), I measure 22-45 mA, and it's very, very erratic, averaging roughly 33 mA, so the math works out. I understand that "normal" quiescent current loss is about 16-18 mA, which implies that my car has an excess drain of 5-28 mA, highly erratic but averaging about 16 mA. That doesn't sound like a lot, but my total actual parasitic loss, combined with my infrequent driving, means that my 12v battery is not kept well charged. I do put it on a smart-ish 2 Amp charger once in awhile, to try to avoid killing the battery, but solving this current leak would help a lot.

-Sean

 

You don't say what the total current draw is directly on the 12 V battery, but the normal draw is 22 - 50 mA. I think you may be chasing a ghost.

You need to have your battery on charge the whole time you're not using it if is not used for three days or more.

I'm not sure what you mean by having a smartish charger, but in order to leave the charger in the long term without having to think about it, you need a proper smart charger that is rated at 3, 4, or 5 Amps.

 

I typically see "around" 20-25 mA draw on a Gen2. I think the infrequent use is more of a problem than trimming 10-15 mA.

That said, get yourself a copy of the factory service manual. There in the wiring diagrams, you'll see that the DOME fuse supplies power to all the interior (courtesy) lights - including the LED in the fob slot.

It also supplies power to the Body ecu and the CM (speedometer).

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Our (3rd gen) usage is down to a trickle now, around 3k kms yearly. Last 12 volt battery went in September of 2015, so coming up on 8 years this fall.

our usage really dropped off with advent of covid, and I was stressing about the battery, looking for excuses to drive. Then started just leaving it on a smart charger, all the downtime.

that’s worked well. We do manage a good drive on a regular basis, due to various factors, enough to keep everything happy. Almost without fail no less than weekly, and a good drive, 10~40 kms. Try to consolidate with chores if practical.

This kind of charging requires secure 120 volt access though, so difficult or impossible, for apartment and street parkers. Not sure what the answer is in those scenarios. Battery kill switch, solar charger?

simple voltage check recently, and do hook up an electronic load tester, for more in-depth assessment, less frequently. Measurements typically taken the morning after a driving day, before charger hookup: