Wonder if someone has an easy solution for this. Neither of the two 12v auxiliary outlets are "switched" by the key. They remain on. I need one outlet that turns off when the key is removed as I just keep forgetting to turn off whatever is plugged into the outlet and the battery has gone dead twice. The H3 is not used all that much.
Jumping a real dead battery in these is not easy. All kinds of noises, and it seems to reset the computer.

Anyway, is there an easy way to make one of the outlets switchable? Appreciate any help with this.

Dave

 

I posted how to do this a while back, but don't know when. Basically, get a 20 or 30 amp, 12v relay (Radio Shack for about $5). Cut the main positive feed into the cigar plug (I think it's orange). Connect the end still connected to the cigar plug to the OUTPUT side of the relay, and the other end to the INPUT side. They'll be 2 more terminals on the relay. One goes to any ground or screw under the dash, the other is your 'trigger' wire for the relay, that you can connect to any wire activated with the ignition switch on. You can use the radio wire (I think it's yellow, verify this with a meter).

 

You could try this
Amazon.com: 12v Cigarette Lighter Lighted Plug, With On/Off Switch (5 AMP Fused): Automotive

It is a simple fix, but you would have to remember to flip this switch too, after you turned off engine.
Broken Halo's idea is a better fix and then you wouldn't have anything to remember

I know that the H3 has some smarts in the CPU that will turn off the lights or accessories if they are left on, to save your battery. I would have figured that the two aux. 12 V ports would have been on the system also.

 

Hello, I'm a first timer here in the forum, and I come from Finland, Scandinavia, Europe. I also own the H2 model year -03, expensive gasoline, but Finland is mainly due to the time a small car the Audi A3 is eating much less gasoline. So is driving the Hummer has less. The root cause of why I signed up here in the forum is that I would like to ask you, which makes the Hummer battery is totally empty, if the car has not been used for a week? Hummer is the heart of the Optima Yellowtop. Thank you in advance for your answers.

with respect
Tomba

 

Welcome.
I've had my battery in my H3 go down twice this winter do to a battery drain on a corode relay in the fuse box. Removed each fuse one at a time and used an eraser to clran the contacts, then did the same for the relays one at a time.
Chris
p.s. You can also use an ameter(amps) to test for a memory/drain.

 

Thank you. I had previously written that I have read tips H2 department, such as the OnStar fuse removal. I'll try this method and I hope this is the solution to the problem. Is H3 models, such as OnStar system?

 

What are you powering with the 12VDC outlets? I used to use one for my radar detector and didn't like the cord hanging across my window so I decided to use the switched 12vdc off the power of the rear view mirror. You'll hack one end but it IS a option.

Or, you could pull the trim piece and locate the hot wire on the outlet you want to power off with the key. Cut it and cap it with a wire nut. Then run a wire from your fuse panel (locate a switched 12VDC location on it) to the cut wire hanging off your outlet. Strip, solder and heat shrink. This is a bad way to do it since your hacking your wiring but it will work fine. A relay really isn't needed.

 

Thanks for all the tips on how to accomplish this. Thankfully no more battery problems.