H2 - Factory radio drawing excessive current
 

Hi.

I searched for a similar problem to mine, and found MANY, but no solutions. So I thought that if I provide more info then someone might have a better understanding.

My 2003 H2 battery dies almost every other night.

I thought that it was the old analogue OnStar unable to connect to the new digital cell towers, so I popped out the INFO fuse. No go.

Current draw is around 3 amps with the truck off.

I used an ammeter and disconnected one fuse at a time (from the fuse box located under the hood). Here are some of the culprits:

UPC/DIC = 480mA
TBC BATT = 60mA
TREC = 10mA
RADIO AMP = 950mA
INFO = 120mA
RADIO = 1.28A

If I pop out the RADIO and RADIO AMP fuses, the current drops to 700mA. I'm not sure if 700mA is within spec, but it sure beats 3 amps!

My truck is completely stock.

Does anyone know why the stock radio would draw so much current?

With the truck running, I even tried turning off the radio via the switch, but current draw remains the same. So basically, whether or not the radio is physically on or not, it is drawing lots of current.

If I don't get a fix soon I'll likely just rig up a DPDT switch under the dash so that I can kill the amp and radio during the night - just so that I don't have to keep boosting the truck in the morning.

Thanks in advance!

Scooter

Re: H2 - Factory radio drawing excessive current
 

Need a new radio. Seenthis problem quite a few times, radio is staying awake and the only fix is to replace or have someone that knows how to repair them fix it. Should only draw somewhere around 50-80mA once all the modules in the truck have powered down and the key is not just turned off but pull it out of the ignition

Re: H2 - Factory radio drawing excessive current
 

Thanks. I figured as much.

I measured ~700mA with the radio fuses out, but I read that I should have waited for at least 4 hrs after removing the key before measuring the current because it takes that long for some modules to settle. I'm hoping that 4 hrs the current draw goes much lower than 700mA or I might have more problems.

I would like to install a computer with touch screen so this might be the push I need! For the time being a toggle switch will be a cheap fix.

Scooter

Re: H2 - Factory radio drawing excessive current
 

Hi.

Well, it's been a while since I last posted but I think I found the culprit. I simply unplugged the fuse to OnStar and have not had a dead battery since.

Scooter

Re: H2 - Factory radio drawing excessive current
 

Good fix. Plus, Government Motors cannot track your every move.

Re: H2 - Factory radio drawing excessive current
 

Just out of curiousity, why would onstar draw so much amperage? Doesn't it shut off if the truck is off?

Do you actually have Onstar or is it on the truck but you don't have a subscription. I'm just wondering if when you have a subscription, perhaps it runs all the time to keep GPS going...

Mark

Re: H2 - Factory radio drawing excessive current
 

I'd have to check but the radio should go to sleep when the key is off. Sounds like an internal short on one of the low current boards. Computer modules go to sleep after 20 minutes, per signal via the serial data buss from the mother computer; BCM.

Onstar does not need to stay on for GPS signals. It only requires GPS if you are using directions or for an accident.

Re: H2 - Factory radio drawing excessive current
 

This is my understanding of the OnStar unit and its built-in GPS:

Your onboard GPS unit is always on as long as the engine is running, even when OnStar is turned off. This allows OnStar to retrieve an immediate location when activated either by you, an accident or the police.

Think in terms of how long it takes for a handheld GPS to figure out where you are at when you first turn it on. A minute or more. You would not want that delay if it were an emergency. And the police can have OnStar give your H2's location in the event it is stolen even when the thief has OnStar turned off.

For the more technically curious, this website has more details about the inner workings of GM's OnStar and GPS system:

http://www.openminds.net/onstar/1explanation.html