Whenever we go on a trip, my truck is not started for 3 weeks.. When I get back the battery is usually dead... I replaced the battery just before last trip and the same thing happened. A check of the battery indicated the cells were OK.. just discharged..... I checked to make sure that the underhood light wasn't on, or any other lights on but they weren't...My question is this..Will the AM/FM/Sirius in dash radio's memory or the aftermarket alarm system draw enough current to discharge the battery down over a three week period? Any suggestions? Once I jumper the battery and get the truck started, it works just fine until the next vacation...

 

Do you have any aftermarket amps? Disconnect the battery before you leave.

 

is there anything else running from your battery, like this guy suggested?

 

At first thought that it might be something in the harness / wiring that supplies power to the trailer hitch plug..BUT.. by looking at the wiring diagram, I see where that circuit is disconnected when the key is off... Maybe the best solution is to disconnect the battery,OR... pull the fuse on the radio then see what happens... I do know that in my boat, when the battery was left in it for periods of time, the AM/FM radio memory would depleat the battery until I installed a radio power disconnect switch..Then the problem went away... I just wouldn't think a car stereo would do the same... No external amps or anything else connected...

 

I know your's is a relatively old post - but I just found I have the same problem. I've had my truck for about 7 months now, and when we went away last September for 4 weeks and came back, the battery was dead. It was the original battery, with some corrosion on the negative terminal, so I cleaned everything up and replaced it with a higher capacity battery.

We just got back from a two week trip, and the new battery was dead. After charging it, I connected an ammeter and found there is a steady 0.1 amp draw on it with everything "off". Now I know this doesn't seem like much, but it works out to 1.2 watts at 12 volts - so over time....

I just have the "stock" radio/6-CD player in the vehicle. The only new "aftermarket" things are a bed cap (with it's high brake and interior lights). An electronic brake controller for the trailer I pull and an Edge programmer.

When Christmas dies down, I'll start disconnecting things and pulling fuses to find the problem. I'll let you know what I find.

- Jack

 

I will eagerly be awaiting the findings of your planned test.. To avoid the problem over the next short vacation cycle we are embarking upon.. I'm taking the truck.. Thanks for the input

 

I'm no wiser than I was. After discoverring how to make the truck "think" the passenger door is closed so I could get to the fuse panel with everything off (thank the gods for this forum) I've determined these facts:

When a door is opened, then closed, the battery drain is about 5.4 amps as long as the interior lights, mirror puddle lights, etc stay on. After about 20 seconds, when they go out, the draw drops to about 0.5 amps - which is still pretty high.

Then, after quite a bit longer (I didn't really time it because I got bored), the drain drops to around 0.07 amps. This was what I found when I checked about an hour later.

Now, I found that the Edge programmer I have plugged in is pulling about 0.04 amps in it's "sleep" mode - at least that's what the drop was when I unplugged it. That means there is about 0.03 amps being used to keep the clock, security system, PCM memory, etc alive.

I'm guessing, right now, that this 0.03 amp draw might be "in spec". It works out to about 0.36 watts and a battery should be able to live with that for a fairly long time.

But, things get complicated when I unplug stuff and plug them back in. For instance, the Edge pulls close to 0.1 amps for a while when reconnected. So, it's a little hard to tell where the electricity is going. I'm also tired of having the PCM get reset everytime I disconnect the battery so I can splice in an ammeter.

I think it's going to take a good day of work and some careful planning to really figure out what's going on. I may just "live" with the "problem".

- Jack

 

Normal occurrence.

Think of how many computers a newer vehicle has these days taking power from the battery even when shut off.

ABS, PCM, GEM, anti-theft systems, radio, keyless entry, and the aftermarket gizmos most put in as well.

For those who have harsher winters to deal with, that's not helping a battery out, either...

 

I am starting to deal with the same issues on my 05, sits too much and even though it's inside these harsh winter temps are really putting a drain on my battery. I noticed the other day after hunting with the truck sitting out in the cold, when I went to start it the battery really drug. Stopped in at a local battery sales place and they said it checked out okay but recommended a battery tender to keep the battery fully charged while it sits in the garage.

Something I'll have to look into, I know allot of guys have them for their bikes.