Greetings:

My H3 (2007) is draining the battery (New Bosch. The batteryis ok.). If I don’t use it for, say, 2 or 3 days, battery goes from full chargeto 12.25 volts (aprox). I disconnected literally everything: Radio, alarm,etc., and it helped just a little bit, but the problem persisted. So I took itto a friend of mine who used to work for an electromechanic (I don’t know ifthis is the right word in English, but I mean the mechanic who specializes inelectric stuff, like alternators, batteries, charging system…), and he told methe problem is a module, most probably the “body control module”, and that thisis a common problem of H3s, Colorados, and other GMC trucks.

Have any of you experienced such a problem?

If so, is it possible to repair the module, or will I needto buy a new one?

Thanks.

 

I have the same thing with my 2007, if I don't drive for two weeks battery is flat, I now use a trickle charger when the vehicle is not being used. I also only get two years out of a battery.

 

Not a BCM failure, it is a circuit that the BCM controls(lights, locks, windows, alarms, accessories, aux power, etc..). GL

 

And how can it be detected?
Is it a short?
Can I detect the exact problematic circuit myself, using a voltmeter or something else?

Thanks.

BTW: In the meanwhile, what I am doing is disconnecting the negative from the battery when I get home. But that's tiresome.

I forgot, in addition to the aforesaid problem, battery cables get really hot, so hot that, when I get home, I have to wait 10 -15 minutes to disconnect the negative.

 

Two weeks? You are lucky, my friend!

 

Check for a parastic draw.

 

I remember a thread a few years back that said the OnStar module could be the culprit. There is a fuse under the hood that I think is on your Positive Battery Cable that can be pulled to confirm. I has been a while back so my memory if fuzzy. You could do a search using keywords OnStar Parasitic drain. Good Luck.

 

Nice truck.

May I ask, when was the new battery installed, and did you have the problem before switching to this new battery? Just because a battery is new does not mean it is OK (It should be, but parts is parts and there are bad ones).

 

hot cables is overcharging while running. volts should not go over 15v

normal drain is checked with a milliamper meter in one batt cable, when first connected it reads apx 1 amp, then drops to 110 miliamp. close doors,no lights on.

1/10 of an amp steady.

 

Thanks for the video. Will do, as soon as I can buy a new voltmeter. This morning, the 9 volt battery in my old Craftsman imploded.