battery drain
 

I had a friend with a o4' silverado. his battery kept draining all the way down. after a painfull and annoying stretch, he finally found that his electric seat had a short in it.

I have a 2007 silverado with 65k miles. I had to have the battery replaced last year because it was low enough to where it would throw a code but always started.

A year later when I go to start it, it cranks slower then usual but always starts. I checked the battery for voltage and also checked it running. Both the battery and alternator check out fine. I am now using the "tow" button everytime I drive it to give it more consistant voltage back onto the battery. My serial number does not fall into the GM service bulletin for a reprogram. I believe everything is working properly except there is something draining the battery when not being used. I have checked battery terminals, cleaned and retightened. I hate to bring it in to the dealership because there is a good chance they won't be able to find the problem.

Any idea's on what could be draining the battery. I'm not running anything on it when it isn't running.

I would have the alternator and battery load tested, only getting a couple of years out of the battery in the gmt900 body is not completely unusual. Just checking voltage with a meter won't do it.

If you have a meter that can measure current, then you could place that between the battery cable and battery and see what the current drain is, then starting pulling fuses and relays till you see a drop...
Be mindful of what you pull as some fuses will force relearn processes i.e. the HVAC fuse and the throttle body... not a big deal but you'll need to be aware of that....

Some items to also check:

Remove any accessory chargers from the 12V outlets

Check that the vanity lights on the visors are not on or coming on...

Reduce the "on" time for the head lights after key off through the DIC

Do you have the after blow feature enabled for the AC, it runs after the vehicle is off to dry out the evaporator to prevent musty smells (this can be enabled disable via the dealer)

I am going to autozone and have them do a load test on the battery and alt. (never knew you could "load test" an alt.

I'll report back, thanks

ive got an 04 thats been running dead overnight......the battery and alternator has been replaced.
im gonna unplug the electric seat and see if that helps.

Battery Rundown
 

Battery rundown is a very large problem and complaint. The battery has very little reserve and was designed for a car not a truck. There's little real estate to do anything else but replace it with another one. I found a system called battery back up system. It allows me to use that extra battery tray they gave me to add a battery. the system is complete and separates the batteries after charging. It charges one at a time so the rate is quite high while not pushing the alternator past it's limits. They have a unique design that uses a wireless switch so you don't have to run wire through the cab of the truck if don't want to. I run an inverter off the second battery for tools and such and it never causes problems with the starting battery. I feel a lot safer off roading knowing I have a backup.

Look up: www.atct-guardiansys.com

It works!

Dbrakeman

Try looking at adding a second auxilliary battery. I use www.atct-guardiansys.com and bought a simple plug n play system to add the battery. I had problem with dead batteries especially around airports. on-star plus other parasystic acitvity run the battery down. The dealer blew me off. I added this system and never worry any more.

Dbrakeman