H2 - Factory radio drawing excessive current

[Scooter911]

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

[Scooter911]

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

[VegasGuy]

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

[OrangeCrush]

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

[f5fstop]

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.

[VegasGuy]

Originally Posted by f5fstop

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

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