The factory alarm will do it also.

I had to have mine on a charger...

Mine would drain in 2-3 days. One night I didn't have my keys so I hit the lock button twice and walked away. I guess I had also forgot to plug it in but I got in it about 8 days later and it cranked fine.

 

Thanks for the tips guys.
I pulled the OnStar fuse, but it rained a little last weekend, so the truck got driven and didn't sit all weekend, so I don't know if it worked or not.
As for turning the interior lights off, I don't see why that make a difference, since when it sits, it sits. I'm not going in and out of it causing the lights to come on.
While it's parked, the doors are always unlocked, so I assume the alarm shouldn't be on.
I thought about adding another battery tender to the garage, but it just seems odd to have to have use one for a daily driver that might go 3 days max without being driven. I use them on "toys", but those vehicles sometimes sit for weeks without being driven based on my time and weather, so it makes sense to use them in those situations.

 

The point of shutting off the light switch override is being that you have the alarm off you would never know if the bcm in the middle of the night decides to think hey the door is open and turns on the lights[killing the battery] thinking the door is open when its really not .the bcm is crap in this truck many problems with.got 63k on my 03 and has been changed twice....

 

I agree.... my rear latch sometimes thinks the rear door is open and gives me notice on the DIC.... and sometimes turns on my lights... it used to set off my alarm....

the fix is $400.... the workaround is free...

I leave the override off.... or on.... whatever kills the interior lights....

 

Hi, I think I have the same problem. I checked key off current and it was about 400ma. Once I pulled INFO fuse, current becomes around 100ma. I pulled INFO fuse out now. Let's see if draining continue.

 

All great ideas!!!!

 

Your not testing it right...thats way to high. You have to wait 15 minutes before taking a reading after you turn everything off. You can't just yank the battery cable and test it either, you need a parasitic load clamp. Put the clamp on the battery and connect the vehicles power, drive it a short distance, park it, turn it off, hook up your electrical tester to the load clamp then disconnect the clamp so the vehicles power is now going through your tester. At this point you have not lost power at any point going to the vehicle. After 10 or 15 minutes, everything should be going to sleep. You will see a dramatic drop. Thats where you take your reading.

 

so, what should it be? the h3 is 110 ma.

if i 'yank" the batt cable and hook up my ammeter it reads over 1 amp for a brief time then it settles at 110 ma.

so why not just unhook the batt and measure as i did on the h3?

like as if you pulled the batt to clean up,then reinstall it? with the meter hooked up.

 

Hi bflorin,

Thanks for the reply.

I could not do the way you suggested. I took the measurement when my H2 battery was drained. Here is what I did.

One morning when I opened the H2 door, there was no light and no sound. I knew battery was drained after 36 hours sitting in my garage. I keyed in and turned but nothing happened. No warning lights lit. I could not even pull out my key.

I opened the food and checked the battery voltage. It was like less then 5 volt in my multimeter. I disconnected negative post and hooked multimeter in between to read the AMP. The reading was unsettled a few minutes but after that it settled around 400mA.

I know 400mA is way too high. So I started to pull fuses and found that INFO fuse was taking huge current. When I pulled RADIO, IPC DIC, HVAC/ELAS, INFO fuse together then reading dropped and settled around less than 100mA, about 70mA.

I hope I was doing this right.

 

Because some possible faulty components may not power up untill the vehicle is driven. Really 99% of the time you dont have to. Its just "the correct" way to diagnose something like this.