khansen46

I used an ODB2 scanner and no codes are present. I've also had it at 2 different shops and they found nothing.

There are no codes present, and haven't been in quite some time. We had some sensors replaced a couple of years ago, but this issue predates that.

The AC was serviced recently, and works fine (except the rear blower, which I mentioned in my post). But I'll run the same test idling in the driveway with the AC (and everything else) turned off this weekend. I'll post the results.

I posted a while back about a parasitic battery drain on our 2000 Suburban. It's an LT 1500 4x4, which my wife inherited from her Mom. I put in an Optima Yellow Top, and didn't have an issue for a few weeks. Then the issue returned. I'm sure the battery just masked it for a while. Prior to that, we went through 3 batteries in about 5 years. Since then, I've kept a battery tender on it to keep it charged. We don't drive it much, so I haven't spent a lot of time troubleshooting. Inspection time is coming up next month, so I've been driving it around lately. I noticed every so often the AC blower would slow down dramatically, all the lights dimmed, and the volt meter dropped to 9. It would last for only a second or two. I timed it while idling, and it happened about every 2 minutes 22 seconds. The RPMs never changed, so clearly it's electrical. The alternator has tested good multiple times at the parts store, but since it's intermittent that doesn't mean much. I replaced the alternator with a new high output one (which is what it came with since it has pretty much all the accessories). I idled it in the driveway yesterday and the electrical only dropped once in 45 minutes. I was pretty optimistic for the first 19 minutes, but my heart sank when it did it again. I've gone through the exercise of pulling fuses, but no joy. I also replaced the AC blower motor a week ago. Apparently at some point while it was sitting for a while some mice built a pretty significant nest in the void above the blower, and the bearings were shot in the blower. Anyway, I know the blower motor isn't the culprit. The rear AC blower isn't currently working, but I doubt that is the issue since it shouldn't cause issues when the vehicle is off. However, knowing there have been mice in there opens up all kinds of potential causes. I'm not looking forward to the prospect of pulling the dash to inspect all the wiring, but I realize it may come to that. All the wiring in the engine compartment seems fine. I'll plan a day to let it run and see if I can find a definitive pattern to the electrical draw or interruption, and then start pulling fuses again. I've already removed power from the DVD player and power inverter, so those should be in the clear. If I still can't figure it out by that point, I may spend the money and replace the computer. I hate just throwing money at it, but it is very sentimental to my wife so I'll do whatever is necessary to get it fixed.

FINAL UPDATE: I bought an Optima Yellow top battery. At over $300, I'll admit it was reluctantly. I started it to make sure all connections were good and shut it off. The Suburban sat untouched for 9 days and it fired right up. I let it run a while to warm up and turned it off. It has now sat untouched for over two weeks. This morning it's 42 degrees in SE Texas. The Suburban fired right up with no hesitation. I've installed multiple new batteries in it the last several years since we've had this parasitic drain, multiple brands. I have read about the electronics drain on batteries from this model. I don't know if the quality of batteries has declined, or if the Yellow Top is just able to mask or compensate for the issue, but it is fixed enough for me. We'll see how the Optima does over time, but I'm happy.

An update on this. The issue still exists. Alternator tested fine at AutoZone and we've gone through a few batteries, so neither is the issue. It's not a constant or predictable drain. I've let it sit 2-3 weeks and it started fine. Last week I drove it around for a few hours after the battery was fully charged, and the next morning it was dead. One odd thing I've noticed. When charging or jumping the battery, it will start and then die if the external power source is connected. I have to charge the battery, disconnect the charger, and then start it. I've never seen that before. I've put a volt meter inline on the positive side and have never seen any abnormal draw. I've randomly pulled fuses but haven't seen any significant or unexpected change in draw. I've pulled fuses and let it sit overnight and still came out to a dead battery. I've been to a couple of shops and they can't figure it out. This vehicle has sentimental value to my wife so we will never get rid of it. If necessary, I'll start replacing electronics one at a time, and the wiring harness if it comes down to it. But I sure don't want to go down that road if I don't have to.

We have a 2000 Suburban 1500 4x4 that my wife inherited from her mother. We've been fixing all the little things here and there, but we're having an issue with the battery draining. If it sits for more than a day the battery goes dead. We've replaced the battery a couple of times in the last 2-3 years. I've used a multimeter and pulled fuses one at a time, but don't see a constant draw. I've disconnected the VCR and power inverter. It has an aftermarket radio, and I've pulled that fuse. Still no luck. One strange thing I've noticed is that it won't run with the battery charger connected. It will start, but dies as soon as I release the key. As soon as I disconnect the charger after charging it, it starts fine. I'm stumped. Is it possible there is an issue with the alternator and/or voltage regulator? Is there something else I may have missed?