Batteries dead, slow drain?

by **Moots1288** » Wed Aug 15, 2012 11:58 pm

Hey guys I have a 06 envoy slt and I've had an on going problem with my battery gauge fluctuating drastically at an idle. I already have changed my alternator and battery within a year and half ago also with my tensioner pulley and replaced my alternator wire with a 2 gauge wire. So with all that 4 days ago I woke up for work truck opened and ran in the morning but by the time I was out of work it was dead to the point of no lights or door locks. So I took the battery out and had it tested and it was no good so I replaced it, but I woke up this morning and ran normal and came home tonight to the same problem I had 4 days ago. I had checked some of the grounds and fuses I have a aftermarket radio and an on board air but I disconnected the on board air. I am thinking it is a slow drain somewhere maybe in the alarm system?

by **06MidnightBlue** » Thu Aug 16, 2012 12:04 am

Is the alarm aftermarket?

by **Moots1288** » Thu Aug 16, 2012 12:04 am

No it has factory alarm system.

by **v7guy** » Thu Aug 16, 2012 2:04 am

I've been doing a little reading and apparently it's relatively common for the ignition switch to cause this, check fuse 22 for voltage.
Also relatively common is a lift gate module... doesn't go to sleep and draws about half an amp, interior fuse box, #3 30A
The XM reciever also can cause a drain, interior fuse box #41
The OnStar module can also malfunction and cause a decent drain even if you don't use it, haven't found the fuse number... maybe #26 interior fuse box
Do you hear a very faint buzzing/humming in the rear area of the truck...there's a fan that sometimes sticks on behind the interior panel.
There's also a ground with a ring connector on the fender that frequently gets flaky, making a poor connection

In the past I've popped a multimeter between the battery and the cable and pulled fuses to isolate the circut. Then I start working down the circut till I find the problem. Takes forever, but it hasn't failed me yet.
I've read mention of disconnecting the battery causing problems too, but I'm not sure how else you'd go about it.

by **KE7WOX** » Mon Aug 27, 2012 2:51 am

Did you find the root of the problem?

So tonight I got back from Mexico and tried to get my TB started, nothing, and the key got stuck in the ignition. I jumped it and drove it to my parking lot, and when I tried to turn it off, the key got stuck in the ignition and I couldn't remove it. Everything is off, however, my Scangauge has a lit screen (but with no info, it's just glowing green), so I removed it to prevent it from draining whatever was left of the battery.

The truck sat in the parking lot for 6-7 weeks with everything off, and something even weirder, is that when I was driving it back to the parking lot all the lights would turn off momentarily (that includes dashboard and DIC), happened like 3 times, sometimes with chimes and error messages on the DIC.

I have a DieHard Platinum battery that was replaced back in Spring Break of 2010.

As of right now I'm thinking I have either a loose side post or a bad ground somewhere, except neither one seems to explain the drained battery. If I can't find anything that doesn't point to the battery then I will probably get it jumped and take it to Sears for them to inspect the battery, which I believe has either a lifetime warranty or a very lengthy one.

Any ideas? I didn't troubleshoot any further because it's pitch black outside and I'm way too tired from traveling.

by **navigator** » Mon Aug 27, 2012 10:34 am

was your scangauge plugged in while it was parked?

by **KE7WOX** » Mon Aug 27, 2012 11:02 am

navigator wrote:was your scangauge plugged in while it was parked?

...yes it was

by **navigator** » Mon Aug 27, 2012 11:08 am

could that be the culprit to the drain?

by **The Roadie** » Mon Aug 27, 2012 11:29 am

My Scangauge auto-offs itself nicely.

by **KE7WOX** » Mon Aug 27, 2012 11:37 am

Mine does too, normally, but I've never left it plugged in for extended periods of time.

by **Moots1288** » Mon Aug 27, 2012 12:12 pm

I have not found the culprit of my drain yet. I disconnect my battery every time my truck is off. I have a feeling it is a computer not going to sleep, because I have not found any fuse that is pulling to many amps when my truck is off.

by **KE7WOX** » Mon Aug 27, 2012 12:54 pm

I found something with mine. The battery ground cable was a tad loose, nothing too bad, but I was definitely able to give it a couple of turns with a ratchet until it was tight. Could thermal expansion cause the ground to get disconnected and then connected again, powering up all the interior and lights momentarily, possibly the alarm too?

I did notice last night that when we jumped it the alarm started going off, but since the last jump was over 2 years ago I don't know if that happens all the time or if it happens when you connect and disconnect the battery.

Moots,

What happens every time you connect the battery? does the alarm go off? what about all the lights and electronics in the interior?

by **Moots1288** » Mon Aug 27, 2012 1:15 pm

When I disconnect and connect the battery the headlight washer sprays for a second then nothing. The ground cable on the battery is dead tight everytime I connect or disconnect it. I also have found it quite odd that my air condition comes on when I turn the key on after connecting my battery again. I do not know it that is a common trait that envoy's have.

by **v7guy** » Mon Aug 27, 2012 4:23 pm

Roadie had mentioned in a previous thread that you won't be able to stick a multimeter between the battery and the cable to test the modules that don't turn off because disconnecting the battery will turn off the modules when they would normally stay on. The tests would show everything off even though they wouldn't turn off normally.
He also mentioned feeding the fuse box while you disconnect the battery cable so nothing was ever powered off. I'm not real sure how you would accomplish this. Maybe a short wire hooked up between the cable and battery, then you could hook up the multimeter between the battery and cable and then disconnect the short wire. At that point all the current should be going through the multimeter and the modules won't loose power and turn off, and you should be able to see a drain somewhere.

I think it goes without saying you wouldn't want to start the truck like this.

by **KE7WOX** » Wed Aug 29, 2012 11:53 pm

Well my problem was solved, the battery had 1.8V and 0.3 CCA when I got to Sears, I got it replaced under warranty, only paid $20 for installation. I haven't experienced any issues yet (except for the A/C vent actuator), so I presume that the loose ground wire was the culprit of the other issues (maybe the dead battery too, I don't know).

YouTube Videos · by **Trail X** » Tue Sep 04, 2012 5:28 pm

Loose ground cannot create a dead battery. Next time you let your truck sit for an extended period of time, just unhook the battery ground. It seems you have some minor draw (could be the SC). Even a miliamp will draw down a big battery given enough time.

V7guy, I think you have the right idea regarding a momentary jumper wire to the fuse box. Could also use a separate 12V battery to simplify the transfer of wires.

by **Moots1288** » Tue Sep 04, 2012 7:49 pm

It was not a ground. Turned out to be a part in the radio for the door chime.

by **KE7WOX** » Sat Sep 08, 2012 1:21 pm

I might have figured out what went wrong with mine.

I normally feed my iPod using a tape adapter, but I keep my old cig lighter powered FM transmitter / dock charger for when my iPod is low on battery or I'm in an interference free zone (since using those transmitters in big cities is rarely successful).

This morning I was retrieving some stuff from the back seat area and noticed that it was connected to the rear cig plug, and rewinding to back before I left, I just remembered that my iPod's battery died when I was in Tucson, so I connected it there for the power and used the tape player for the audio. Since this is not just a cable but has a built-in transmitter, the LCD and the transmitter were taking battery power since July 1st.

I completely forgot about that one, and even though all my other electronics were disconnected, that one stayed connected.

Offroad Trailblazers and Envoys