i purchased a 2007 in august my electrical problems included false readings of 4 wheel drive failure and gps not operating at times. then came dead batteries even when driving for miles turning off the truck and coming back 15 minutes later to a dead battery. the truck starts quick and battery is either strong or completely dead. After 2 trips to gm dealer the truck did the same thing for the dealer -they had to tow it back to thier shop but could find nothing again. everything comes up green on their computer except replace battery. I have been told there is no or very little drain . Any ideas-as GM case manager and service reps cant find it. the truck has 4800 mi. and is located in MAINE but problem seems to have nothing to do with temperature or moisture. thanks doug

 

Hello Friend, Your vehicle is a 2007 Hummer H?.
Your battery in obviously not getting enough of a charge due to a loading (short) condition.
You should go to an specialized auto electromechanic where a short can be traced with specialized diagnostic equipmet.
Also you may want to try the Following:
1) Set your parking brake
2) Transmission in Park
3)Turn on your vehicle
4) As it is idleing, remove the positive (red) cable from the battery.
Be careful not to let any part of the positive metal lead touch any part of the vehicle.
You may want to wrap the positive metal lead in a rag so that it won't touch anything.
5) Upon removing the positive cable, did the vehicle turn off by itself?
If yes, you may have a faulty alternator
If no, get a volt meter and check the volts between the removed metal lead and the negative ground.
It should be around 12 volts.
If it is less than 12, you may have a faulty alternator or something (a short) is loading down the voltage from the alternator.
6) You'll have to try now removing and replacing some fuses systematicly , one by one and checking the voltage each time you remove a fuse and through process of elimination, when you get a sudden increase in voltage, you will probably find the module that is shorting out the alternator.
Also even though it is a fairly new vehicle you may have somewhere a harness kink, wedge or chafed and is affected only when the vehicle is in motion.
Good luck! Keep us updated!

 

This has happened to others and found that the following ( BCM component) also contibuted to the problem. You might want to tell the Dealership to check this as well.

The Body Control Module (BCM) supplies vehicle occupants with visual and audible information and controls various vehicle functions to provide and receive information.

The BCM provides the following features:
• Automatic door locks
• Battery protection
• Chimes
• Compass/mini-trip support
• Courtesy lamps
• BCM diagnostic support
• Door lock inhibit
• Headlamp time delay
• Ignition key lamp
• Illuminated entry
• Instrument panel dimming
• Mechanical instrument cluster support
• Power door locks (with/without remote keyless entry)
• Sliding door memory lock
• Vehicle Theft Security system (VTSS)
• Windshield wipers / washers (front and rear)

Body Control Computers
The Body Control Computer is a new way of combining seperate systems into a computer that receives and transmits information. This new system reduces the number of modules and wires needed to preform various functions, such as, intermittent wipers, seat belt reminder, ignition key light, climate control, vehicles mileage, etc.

 

DId you ever find a solution to your problem. I have a 06 h3 and 800 miles after the warranty i went out to start it and click, click dead battery. I figured something was left on so i jump started it and ran it for a hour then the next morning the same thing. I took the battery to autozone and it checked ok, they put a full charge on it. I put the battery back in the h3 and started it up, while it was running i disconnected it and the hummer kept running off of the alternator alone. measured 12v from metal lead to the negative like safarihummerh2 suggested. Then the h3 ran fine for 2 weeks and today, click click. great.. any ideas.. and where is the bcm module that was mentioned and i bet it is expensive.

 

just wanted to throw out an oohrah! to a fellow marine! good luck on the hummer

 

This is sounding like it's becoming an increasingly common problem. On the H3 sub forum there is a thread devoted to this issue.

I have myself found a dead battery this week in my 2007