Battery Drain On '03 1500hd.....

sirjeffro · January 22, 2009

I read in the "full-size" section about a TSB from late 2002, #02066 Battery Drain. See the post here- http://www.gm-trucks.com/forums/index.php?showtopic=14362

It refers to several GM models and gives VIN ranges. Mine is not in the range listed, but.......

I am wondering if this BCM re-calibration is available other than from a dealer? Has anyone had this re-calibration done? My truck (2003 1500HD) is not within the VIN range listed in the bulletin but seems to have parasitic draw that will nearly kill an Optima red-top overnight. I know, I know...the curse-ed Optima. So I charged up the OEM Delco and put it in and exchanged the red-top for another one.

The OEM battery has been doing a fine job since Saturday Jan. 17, 2009. Now I detect that each day it is a little more sluggish but has yet to fail to start the truck. I am going to use a battery disconnect switch to try to track down the drain.

Any advice, insight, or revelation will be greatly appreciated.

Best regards,

Jeff P.

Kodiak450 · January 22, 2009

I never heard anything of a battery drain problem, but some things I encounter with my 03 is after locking the truck via remote and activating alarm, I hear a warning sound going off. I don't know why this happens, and it happens every now and then. I recently just replaced my battery yesterday, which was the original battery too! Lasted 6 years, and I am running alot of stuff too. A plow, an powerful sound system, a 1700 watt inverter for my lap top and printer, alarm, ect. I decided to stick with the Delcon professional series battery ($129.00) seeing how it is a 6 year battery. Those optima batteries, I found out that they are not the best choice for replacement, something to do with the voltage draw?

To get back on topic, I would make sure that your truck does not have any accessory light staying on. You could have inadvertly pushed a button and don't realize it because of the delay of the lights that stay on for X amount of seconds when you turn off the truck, then walk away. I always make sure I do not leave any kind of charger, or componet that plugs into cigarette plug adapter in when I am not running the truck. Cell phones chargers, GPS chargers, ect, could consume power even though nothing is on, or hooked to cord. Even with certain plows, the older style in particular, I was once getting a bad power drain from the plow light switch. I would've never suspected the plow lights would have done this when the truck was off, the lights weren't on for one, but the power was being drained regardless. Anyway after installing new battery yesterday, I noticed my headlights seemed brighter, and my 2 channel amp that powers my 2 12" speakers in my kicker box sounded better. I guess this last year my alternator was working harder, because battery got older and was weaker, but still 6 years for a battery is great!

bill190 · January 23, 2009

Is everything electrical on the truck stock? Or has there been electrical gadgets and wiring added?

I've seen all sorts of stuff added to "always on" circuits, then people have trouble with their battery going dead. (As well as fuses blowing because they add everything to the same circuit.)

I just added a bunch of electrical stuff to my truck, but made a point to only use "ignition on" circuits. When the key is off, so is all of my add-on electrical stuff. However nothing I added needs to have power to retain memory or whatever.

sirjeffro · January 23, 2009

Hey guys, thanks for the ideas. I do have an air compressor, but that was the first suspect I eliminated. The compressor power comes from the battery connection on the back of the alternator with and inline fuse. Then through a relay. The relay gets power from an "always-on" lug in the under-hood fuse box, again with an inline fuse. I pulled each of these fuses in turn and still had the "dead battery" problem.

No other accessories or plugs/cords. These items are not even in the truck unless they are being used on a trip or specific "project."

Oh wait..... I have a rear led light strip. I'll be sure to double check that as well.

Now that I have the battery-disconnect in place I'll be able to test for a draw after the BCM has "gone to sleep" and, I guess, start pulling fuses.....

Anybody else had the type of problem?

Thanks again,

Jeff P.

bill190 · January 23, 2009

A relay is just an electric switch.

There are the "switch activating connections", one of which would typically be connected to a manual switch, say like a fog light switch on the dash or a headlight switch on the dash. You turn on the switch on the dash, then this supplies power to the relay.

Then there are the "switched connections" on the relay. When the relay is activated, power is supplied to the device (fog lights, headlights, etc.)

The advantage of a relay is for devices which use a lot of electricity and need large size wires. The relay itself does not use a lot of electricity, so you can run small wires to the dash board and dash switch to activate the relay. And keep all the large wires under the hood.

An example of this is the starter. A starter needs very large wires. Imagine running those large wires to the ignition switch inside the truck! It is much better to use a relay, run small wires to the ignition switch, and keep the large wires under the hood.

In my case I used relays for my various devices. And each device has a switch on my dash to turn it on and off. Actually the switches are just turning on/off the relays.

BUT I connected my dash switches to "ignition on" circuits. This way, if the ignition is off, so is power to the relays and power to the devices is off as well. If I accidentially leave a switch on, power will still turn off to the relay and device. (And not drain my battery.)

How relays work...

http://en.wikipedia.org/wiki/Relay

Diagram of a relay...