Tahoe battery drain

[Torqued]

My daughters Tahoe has started draining the battery when sitting for 3 or 4 days. I checked the draw on the battery when everything is off and it draws about 200 mA when the vehicle is locked and about 65 mA if left unlocked. All of the draw except about 7 mA is through the TBC fuse which is for the keyless entry and body control module. What I want to know is if this amount of draw is normal or too high.
They disconnected the battery for a week and it held its charge with no problem, but when hooked up, it lasts only a day or so.

Thanks in advance

[MT-2500]

It is to much draw.
Strange on the unlocked and locked draw.
Check and see if you can find a relay for lock and unlock.
What year do you have?

[Torqued]

Sorry about not mentioning it. It's an '01. I don't have a service manual of any type for it. I'll be out looking for a used factory one. Sounds like time for a trip to Ebay.
If I were to guess, I'd think the difference in the draw was due to the security system armed when it was locked. Still seemed like a lot of draw to me. Now to figure out why.

thanks,
Torqued

[MT-2500]

10-4 on e bay.
Also public Libraries have a lot of repair info.
Run a google search.
And also. 24.95$ us a year. For a online subscription.
http://www.alldata.com/products/diy/index.html

[2000CAYukon]

Is the battery original?

//2000CAYukon

[Torqued]

The battery is a little less than 3 years old. They used to drive it daily and never had a problem. Now they both drive cars to work and this raised its ugly head since the Tahoe sits for a week at a time.

Thanks,
Torqued

[Treblig70]

had a friend who had the same problem with the battery draining over one or two days if he didn't drive the truck. He fought the problem for about a month before he happened to go out to his truck late at night and noticed that one of the vanity mirrors [sun visor] was on. He opened the truck, the mirror door had come dislodged and wasn't closing the switch. He was sooo happy because he was fixin to pay for an electronic check to find the reason for his battery drain.......Gil in Tex

[BLUE ZL600 EFI]

I have two possible solutions for you. My buddy's 03 does this and he found out he cannot lock with the remote. Try just locking with the button on door for a few days. It turned out the factory alarm system was shorting.
Now I had the same problem on my 01. I checked all circuits and could not find any draw on any fuse that was not normal. Tured out it was a shorted cell in my 1 year old battery. Just started all of a sudden. I would look into that first.

[J-Ri]

Originally Posted by Torqued

My daughters Tahoe has started draining the battery when sitting for 3 or 4 days. I checked the draw on the battery when everything is off and it draws about 200 mA when the vehicle is locked and about 65 mA if left unlocked. All of the draw except about 7 mA is through the TBC fuse which is for the keyless entry and body control module. What I want to know is if this amount of draw is normal or too high.
They disconnected the battery for a week and it held its charge with no problem, but when hooked up, it lasts only a day or so.

Thanks in advance

200 mA is probably ok, 50 mA is generally the highest you want, but probably wouldn't cause a dead battery after only a few days. Check for a "case draw". Touch one lead of a voltmeter to one terminal and touch the other lead about 1/2" away from the other terminal, so it's touching the plastic. If it reads near battery voltage, take both terminals off (may as well remove the battery from the truck so you can clean the whole thing), clean them (the battery contact and the cable ends) with a baking soda/water mix and a wire brush (about a cup of baking soda to a gallon of water), then clean the entire battery with the same mix, but use a rag or a nylon brush. Rinse it off with clean water and re-check.

If it does have the case draw, it's basically like having a big resistor across the terminals all the time, which doesn't show up when doing the standard parasitic draw test.

[J-Ri]

And I forgot to add, make sure the vent caps are on tight, and don't let the baking soda sit on there longer than necessary. Assuming you have the factory side posts, you could avoid the top of the battery if you want.

Oh, and did you check the electrolyte level?


EDIT:
I just re-read your post, and saw the 200mA was with the secutity system on, your numbers are fine where they are. And even if the battery is 3 years old, a lot of the cheap ones will fail in two years or less (once saw a battery 14 months old that was JUNK... We don't generalize brands... but this battery would "neverstart" the car). Load test the battery if my "case draw" idea doesn't fix the problem.

[BLUE ZL600 EFI]

[ Load test the battery if my "case draw" idea doesn't fix the problem.[/quote]

That's what we did when we dicovered my battery to be bad. It was about 9-10 months old. We load tested once and it started to drop off. By the start of the second load test (about 5 min later) we had it smoking. I took it back and got a replacement under warranty and it's been fine for close to 2 years now. By the way it was a Optima red top battery.

[carpenterkc]

I am currently having a very similar issue with my 2003 Tahoe. battery dead in short time. I have a remote start system, but have tried unhooking it.

observations- battery will go dead in 24 hours, or sooner. took it to napa and had a buddy check the charging system, and did a load test with an analog load tester. both check out. pulled negative battery cable, hooked up voltmeter between cable and post, set on dc10A. once the connection was made amp draw spiked to 3 ish amps until everything including the CD changer reset and shut down. meter reads 0.26 amps. so i started pulling fuses. pulled the 15 amp radio fuse and the amp draw immediately dropped to 0.03 amps.

this is where it gets complicated. after driving it for an hour home last night at 9:30 and my wife driving it to doctors office at 10:00 this morning, the battery was dead before soccer practice this evening. This occurred with the radio fuse OUT!!! I'm losing my mind and cant afford to pay for maybe.

as far as unhooking the remote start, I pulled the lower panel under the wheel and unhooked all of the taps into the factory harness. and for the bad diode in the alternator, wouldn't that show up as a draw on the voltmeter?

I'm sure I am missing something here, any advice at all would be greatly appreciated.

[MT-2500]

Originally Posted by carpenterkc

I am currently having a very similar issue with my 2003 Tahoe. battery dead in short time. I have a remote start system, but have tried unhooking it.

observations- battery will go dead in 24 hours, or sooner. took it to napa and had a buddy check the charging system, and did a load test with an analog load tester. both check out. pulled negative battery cable, hooked up voltmeter between cable and post, set on dc10A. once the connection was made amp draw spiked to 3 ish amps until everything including the CD changer reset and shut down. meter reads 0.26 amps. so i started pulling fuses. pulled the 15 amp radio fuse and the amp draw immediately dropped to 0.03 amps.

this is where it gets complicated. after driving it for an hour home last night at 9:30 and my wife driving it to doctors office at 10:00 this morning, the battery was dead before soccer practice this evening. This occurred with the radio fuse OUT!!! I'm losing my mind and cant afford to pay for maybe.

as far as unhooking the remote start, I pulled the lower panel under the wheel and unhooked all of the taps into the factory harness. and for the bad diode in the alternator, wouldn't that show up as a draw on the voltmeter?

I'm sure I am missing something here, any advice at all would be greatly appreciated.

If amp draw is within specs and it is charging goo while running and battery goes dead sitting you may have a bad battery with a dead cell.

Have battery tested and if it goes dead with battery unhooked batery is bad.

[j cAT]

you need the battery load tested. then remove the alternator output wire check for battery drain current. also what is the voltage with a voltmeter acrosss the battery , with the engine running when cold then when hot.

have all the lights/ac on max etc. on the voltage checks.

what year and mileage ? any aftermarket alarms/radios/amps etc.

[carpenterkc]

I had the battery load tested, and i removed the alternator and had it tested. the load test did not show a dead cell in the battery and it was making 790 cranking amps(800 cca battery).

I retested the draw with the alternator off----Still .03 amps. I pulled every fuse in the fusebox under the hood, and the panel at the end of the dash. No change from .03 amps. I pulled one fuse from the remote start system and the draw dropped to .01 amps.

can a battery not show a dead cell and still be going bad?? the reason i ask is that this is the third battery I've put in the Tahoe since 2005 when I bought it. and it seems that the longer the battery is in there the more pronounced the problem becomes.

the radio fuse under the hood creates a .23 amp draw after resetting and shutting down, is this normal?

There has to be something I am not seeing, but it's hard if you don't know what you're looking for. I have always turned my own wrenches including 5 sets of intake gaskets on various vortec's. but I am whipped by a gremlin in the wires.