Parasitic Draw - usual suspects?

[Joe]

Well. from my previous post I've been fighting a dead truck for about a week.

Decided this weekend to replace the battery and also had the Alternator fail the regulator test. FIgured between the two I would easily solve the problem. No such luck. Came out today and dead again.

Suspect at this point it has to be parasitic draw. Any thoughts on some of common suspects for this. I do realize it could be just about anything.

I just pulled the fuses tonight for radio and onstar to start the process.

Thanks again all.

[[__--MUD--__]]

any accessories connected directly to your battery, not going through stock wiring?

think it was back on my 1st power issue, since I had a brand new HID light setup connected directly to the battery, I assumed it was good. I was testing **** for days...by chance buddy of mine noticed the headlight realy was warm... That was my draw. My point is dont assume anything, test it all and keep the variables consistent.

[Joe]

thanks. I pulled the radio, radio sub, and info fuses and its been good for the last three days. Planning to dig deeper in to it this weekend but hoping its the Onstar as that's an easy one since I dont use it. Little concerned though that it is the radio. It was acting funny beforehand in that it was getting horrible reception when it shouldn't have.

[[__--MUD--__]]

Are you actually taking any amp readings or just pulling ****? What draw are you getting right off the battery?

You need a good digital auto rangine meter to do this. When you first turn the truck off it will be in a higher amp range, which will drop down to a lower range after 10 minutes or so. If your not sure what your doing, you'll smoke your meter.

Someone posted the mah draw numbers a while back on all the common circuits that retain power when the vehicles off...I used it tracking down my issues. Might of been Easy Ed.

Did you try searching the forums for "parasitic"?

[Joe]

Just pulled the fuses (one's often the most suspect) at this point as I was out of town for work this week. Really just wanted to take a swing and narrowing down the problem. I do have a fuse tester/meter as well as a multimeter and will dig deeper over the weekend.

[Joe]

Looks like the Radio is indeed suspect.

Radio Fuse is pulling 1.1-1.2A key out, no power to truck
Radio Sub is also pulling 1.0-1.1A key out, no power


I am guessing this pull is out of bounds...

[[__--MUD--__]]

I dont think you have let the body control module go to sleep. After you shut the truck off it takes few minutes, opening a door, Pulling a fuse, keyless entry, etc.. will wake the system back up. I dont think you can go off the interior lights as an indicator either.

Where ever your taking this reading, hold it there or jam the meter tips in so you can get a reading after 10 minutes.

The draw your saying would kill a battery in 3-5 hours.

The factory spec when all modules are asleep should not exceed 25 mA.

25 mA should last 30 days
250 mA draw would kill a battery in 3 days.
750 mA - 1 day

How long is the truck lasting before it wont start?

Do you have or know someone you can borrow a parasitic load switch from? Really need to know what your pulling right at the battery...which will also indicate to you when the system goes to sleep.

[Joe]

I dont have a parasitic test switch but considered buying on. Just not easy to find.

I tested the fuses using an Electronic Specialities Fuse Buddy Pro.

The battery would die overnight but has been fine for the last couple of days with the fuses mentioned earlier out. The INFO fuse was showing 0.0-0.2 draw

I did wait for the cooldown, twice in fact.

Plugged the radio fuses back in to see what happens overnight again, may not even take that long to verify.