'03 Yukon battery drain?

Greetings. I usually reside over at rec.motorcycles.dirt, but am looking for help on my Yukon XL.

Battery went dead a couple times over the course of a month and I figured it was time for a new battery. Dashboard ammeter indicates charging system is OK, the battery was at least 55 months or so into it's 72 month rated life.

In the process, I checked for anything that might be draining the battery down, and found a 1.3 amp drain with key off and out. Is this normal? I wouldn't think so, but I realize there are some circuits that must stay live.

I then put a light-em-up circuit tester in line with the neg terminal of the battery and the neg. cable, and proceeded to one by one pull every fuse in the panel under the hood and at the left end of the instrument panel. Light stayed on the whole time.

It's been suggested it could be a bad rectifier in the alternator, but I'd appreciate any pointers on whether this is an abnormal situation or not.

Suggestions on what to do next are appreciated.

Reply to
HardWorkingDog
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If you think it might be the alternator, you could remove the wire (s) from it while monitoring the current draw.

Reply to
Meebers

Yup, it had occurred to me, haven't got arountuit yet though. Still curious if this is abnormal or not.

Reply to
HardWorkingDog

Anything over about .3 Amp would be abnormal.

If it's the alternator it will be warm to the touch in the morning.

Al

Reply to
Big Al

1.3 amps isn't enough to drain a battery overnight but isn't normal either. Pull the plus cable and any plugin lead off the alternator and see if the current drain stops. If so you may have a leaky rectifier in the alternator.
Reply to
Meat Plow

Pulled both cables off the alternator, still draining current. I did it this evening in the dark, and when I put my lamp circuit tester on it, I realized the circuit is pulsing dim-bright, dim-bright, dim-bright.

And I could clearly hear something power up near the firewall/steering column area whenever I put the ammeter or circuit tester in place.

Reply to
HardWorkingDog

Good news it isn't the alternator. Bad news is you might want to contact a local GMC dealer and ask them as it's anyone's guess what you're hearing and if it has anything to do with the current draw. Some thing else to consider is unless someone can chime in and say from experience with an 03 Yukon or Tahoe or Suburbon that 1.3 amps is definitely too much draw, it may not be depending on the accessories etc...

Reply to
Meat Plow

Yeah, that's pretty much what I've come to. Bottom line, everything is working normally, and since I replaced the battery it's been starting up just fine.

Thanks all.

Reply to
HardWorkingDog

How long does this current drain last? On most of the newer vehicles the different computer modules and the RAP module stay on for 15-20 minutes. That could be the drain your seeing. Try measuring it again and wait for 20-30 minutes and see if it has dropped down.

Reply to
Steve W.

Thanks. Last time I checked, I waited a good 40 minutes, with no change.

Reply to
HardWorkingDog

I had a similar issue with a 2002 Tahoe. Turned out that it had a gravity switch for the underhood light, and it wasn't turning off when the hood was put down. I pulled the bulb, and no longer had the issue.

John

Reply to
John

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