Defective BCM? (Body Control Module)
 

07 H3 Monsoon w/GPS unit had to be replaced due to blank screen and sometimes wavy lines ... also had BCM (body control module) changed out because the truck wouldn't start, nothing but intermittent turning over but no start ... really weird stuff man ... then the 2nd Monsoon unit started acting up so I went through the electrical system piece by piece and found a hairline crack in the positive battery clamp (a real cheaply made piece of crap) ... that was the real problem ... an intermittently loose connection causing havoc with the sensitive electronic chips ... soooooo ... I changed out both battery terminal clamps to a nice set of gold-plated compression-fit battery terminals, put in a new red-top Optima battery while I was in there and all my electrical problems disappeared instantly. Get rid of those cheap battery clamps and put a real set of battery terminals in your H3!

Excellent post...I'll change out the battery terminal clamps first but if that doesn't solve my electrical issues then I'd like to know: can you replace the BCM yourself or do you have to take it to a dealer?

Geez you guys should use the search feature more often... been there done that...

All parts (Dual optimas race application, 4x tsunami multi port terminals, 200amp solenoid, hi output wiring) provided by www.Ridgedemon.com

Interconnection Resistance and Why It's Important.
 

Geez you guys should use the search feature more often... been there done that...???????

Been where ... done what? I did use this sites search feature for "BCM" and guess what ... NADA ... ZIP ... No Results Found.

BTW ... your link is nothing more than a pieces/parts advertisement for an after-market supplier.

Now back to the point of this thread ... specifically high interconnection resistance at the battery termination. Interconnection resistance is measured in micro-ohms. The lower the reading the better the termination. Both of my H3's measured >50 micro-ohms of interconnection resistance at the factory OEM battery clamps. After re-terminating the battery cables on heavy-duty battery terminals the readings dropped to <4 micro-ohms.
NOTE: Micro-ohm meters are expensive. I used an ALBER CRT-400 Cellcorder http://www.alber.com/ProdPageCellcorderCRT400.htm for these tests. They cost around $6,000.00 with spike probes.

My background in DC power goes back 40 years. Originally trained by Bell Labs, 20 years with AT&T, and now testing stationary backup DC power (batteries) for nuclear power generating plants throughout the mid-western United States.

RECOMMENDATION: Your GM dealer (or after-market pieces\parts supplier) probably has no idea what interconnection resistance is and they do not have the proper test equipment to measure it anyway. Look in your local directory for a "Standby Power" company; find one that performs maintenance on DC Backup Power Systems aka "Stationary Batteries". They will have the proper testing equipment and expertise to test your battery terminals interconnection resistance and tell you whats really going on. If the readings are high, you have just found the source of many both hard and intermittent electrical problems, the fix is now easy ... re-terminate those connections. If the readings are good look somewhere else for the root-cause of your electrical problems. Remember to use a good quality battery terminal grease on your connections, we use "No-Oxide A" compound on all our battery terminal connections, it will stop oxidation. It's also a good idea to check and re-torque your battery terminal connections at least twice a year. Good Luck!

I was referring to the the battery terminals and not the BCM... I included the pic of what I did when I was getting intermidiate power failure on my H3... The website I provided is for a fellow Hummer owner that has and is constantly Persuing upgrades to our vehicles, to make them safer/and more reliable, so put his link up is nothing but a positive nod to him and the leaps and bounds he has been making...

As far as the BCM goes, it's in a pretty tricky spot and am not sure if you need to remove the dash or just the kick panel... Once replacing the unit I don't know if here is a relearn that needs to be done either... But keep us posted if what you go forward with

@runamok, how difficult to replace battery cables? I have same problem on my 2007 H3 with only 22k miles. According to local GM dealer, says BCM needs to be replaced at a cost of $1,045.

@ak47dennis, thank you for the reply, after reading it i questioned the dealer and the repair is for replacement of the generator/battery control module (part of battery cables), part cost is $410 + 3hours labor = $455 = $898

see my other post abt cables,,,hummer wont start

thank you drtom!