My '05 Quadrasteer never sleeps. It burns electicity day and night, key in, key out, lights on, lights off. It's an insomniac.

Botton Line Fact: It draws 2.55 amps just sitting there doing absolutely nothing.

No doors were open... (well, the hood was open, but we all know GM thrifted out the underhood light back 2 or 3 years ago). No radio playing. No key in ignition. No lights. No nothing.

2.55 amps is a lot of current to keep alive radio presets and ECU codes. 2.55 amps is darn near enough to weld tin foil if you work the puddle right...

So what inspired this test?

I was exchanging coresspondence with someone yesterday and the subject of parasitic battery drain on our vehicles came up. I decided that the issue was significant enough to try to quantify in some type of way, for a factual foundation.

My quad is an '05, so I've never had occasion to disconnect the battery before, but I HAVE had to CHARGE it, which I thought was a little rank for a brand new vehicle, but I chalked it up to the car sitting on the dealer's lot for a while.

When I went to disconnect the terminals, right away I knew something was cooking, because of the faint but sharp, snapping, arcing clicks I heard. I donned a safety shield and looked down there while under my shade tree and I could see needle thin light arcs that extended up to 1/4 " long in random directions as I removed the battery cables.

Hmmm, I thought. This had never happend in any of my [Your Preferences Settings do not allow competing brand names to be displayed] trucks.

Then I found something else unseemly for a brand new vehicles: corroded battery terminals.
They appear bright and shiny on the outside, but once unscrewed and completely removed, corrosion crusted the threads... like this:

And like this:

Recognizing that corrosion would be the cause for increased resistance, but not the root cause of the arcing, and hence the amp draw (which I hadn't measured at that point yet), I still needed to meter what was going on.

But a little housework on the battery first...

A tiny wire brush is chucked into the end of a high speed rotational pencil wand "Dremel" tool, to clean the inside threads of the terminals:

For the test, I thought I might try a known good battery... one that is fully charged, as the test indicator on this commercial jumpstart unit shows below. The picture doesn't show it, but this portable battery case stands two feet tall.

Now, not knowing just how much current was flowing, and yet wanting to use an instrument sensitive enough to detect flow down to the milliampere range, I had to first fuse test the draw.

Once I determined that a five amp fuse would not blow, I had no qualms about hooking up my DVOM, which is fused at 10 amps.

Five amp shown remaining intact below, while connected between the test battery and the load:

Now for the test:

The current fluctated between a fairly narrow range... plus or minus 20 milliamperes. That is pretty much a steady state draw. Here is photo of the low side of the measurement, at 2.53 amps :

And here is proof positive that my Quad suffers from insomnia. 2.55 amps. Heck, I don't think my curly flourescent porch light burns that much current.

2.55 is where the meter sat most of the time. The test was conducted after the vehicle sat for hours. The test was also conducted on both the postive and the negative side of the circuit. And the test was conducted after the battery was connected for longer than 20 minutes.

I don't know what is using up so much current.

Is it big brother? This car does have 3 satellite antennas (TNR GPS Navigation, XM Radio, and Onstar) and a built in factory telephone... are those devices talking to the sky behind my back? They shouldn't be. They're supposed to be working for me.

Is it the ECU? BCM? etc? The various computers in the car keep time, and remember data, settings, codes, etc? But do they really need 2.55 amps for this activity?

This is an open invitation for anyone interested to check their current draw, report and compare to see what is normal.

Thanks!

Facts, that was quite a discovery and quite an informative post. That is also quite a bit of drain for a vehicle to be just sitting there...

Are you gonna find the individual circuits responsible ?? That could take some detective work, but I already know- if there's some researching to do, you'd be the guy

I'm gonna check mine tomorrow and see what my draw is. I've been meaning to do mine but have been so busy, just ain't had a chance.

Very illuminating post, Facts !!! I'll be following to see if you find where it's all going.

Hmmm.... Big Brother, huh..... One reason I'm glad I don't have OnStar. Although I know that certainly doesn't mean they don't have some other little bug in there...

quote:

Are you gonna find the individual circuits responsible ?? That could take some detective work, but I already know- if there's some researching to do, you'd be the guy... Very illuminating post, Facts!!! I'll be following to see if you find where it's all going.

I'm not so certain where to go from here... because I won't know whether I really have a problem until A) we hear from other owners what their resting current drain is, and or B) I am able to obtain a factory specification, service, and electrical diagram manuals in order to poke probes more intelligently.

My initial motivation for checking the drain was to provide a reference point for anyone who would be interested to know how much parasitic current draw might exist on a stock '05 vehicle.

If a few others check also, we might be able to collectively put this data into proper perspective before tearing into the electrical system.

This message has been edited. Last edited by: Quadrafacts,

Heck, I just figured pulling fuses on different items could narrow it down.

If you found your dual-ride shocks, at rest, are pulling ANYTHING, that would be a pretty good indication...

The radio, OnStar, maybe navigation systems, I would assume all have a constant flow going thru them, but if you found it to be more than just a few milliamps, that too could indicate an issue.

But, true, w/out knowing exactly what specs are, you'd basically be guessing...

Ahhh, I think I can read between the lines there on the dual ride shocks... I could test those, but know that I do not have switch selectable "dual ride" shocks. I have the "Autoride" shocks that have no dash switch... so I would guess that the electronic modules might be different.

Have you checked your drawz yet?

Heck no

I keep myself too busy sometimes

I'll try to spend some quality time with Quadzilla tonight !!!

Here's what the GMC Shop Manual for 2005 says.

As an example, for a 690 CCA battery with 110 min. RC (60.5 AH) starting at 80% state of charge, a constant current drain of 2A could run the battery down to a 50% state of charge in 0.4 days, 750 mA - 1 day and so on.

The manual calls it "parasitic current drain". I couldn't find any specific number, except for a formula related to battery capacity and amp hour rating. "Divide the reserve capacity by 4, amp hour rating by 2.4". Example - for a battery with a reserve capacity of 100 minutes (60A/H)
the current drain should not exceed 25 mA. The battery installed in my truck has a 115 minute Reserve Capacity Rating, which translates to 28.75 mA drain.

The manual talks about "modules going to sleep" (including On-Star) and waking up periodically.
The manual does describe the fuse removal approach for isolating the problem - but this will only identify the circuit, not the specific part.

The tool used for testing is a J 38758 Parasitic Draw test Switch.

This ain't no simple problem.

Mr Q,

Have you checked yours yet? how did it compare to the above results?

I'm very interested in this as you might imagine.

Thanks, Eric

Eric, tonight, FOR SURE !!!!!!

It never seems to slow down for me

I posted a snipet of my weekend, I think in 'Facts thread on the skid plates... Wasn't a good one

And now it's Monday